## Nitrogen – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Nitrogen is 1.04 J/g K.

Latent Heat of Fusion of Nitrogen is 0.3604 kJ/mol.

Latent Heat of Vaporization of Nitrogen is 2.7928 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Nitrogen – Properties

Element Nitrogen
Atomic Number 7
Symbol N
Element Category Non Metal
Phase at STP Gas
Atomic Mass [amu] 14.0067
Density at STP [g/cm3] 1.251
Electron Configuration [He] 2s2 2p3
Possible Oxidation States +1,2,3,4,5/-1,2,3
Electron Affinity [kJ/mol] 7
Electronegativity [Pauling scale] 3.04
1st Ionization Energy [eV] 14.5341
Year of Discovery 1772
Discoverer Rutherford, Daniel
Thermal properties
Melting Point [Celsius scale] -209.9
Boiling Point [Celsius scale] -195.8
Thermal Conductivity [W/m K] 0.02598
Specific Heat [J/g K] 1.04
Heat of Fusion [kJ/mol] 0.3604
Heat of Vaporization [kJ/mol] 2.7928

## Oxygen – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Oxygen is 0.92 J/g K.

Latent Heat of Fusion of Oxygen is 0.22259 kJ/mol.

Latent Heat of Vaporization of Oxygen is 3.4099 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Oxygen – Properties

Element Oxygen
Atomic Number 8
Symbol O
Element Category Non Metal
Phase at STP Gas
Atomic Mass [amu] 15.9994
Density at STP [g/cm3] 1.429
Electron Configuration [He] 2s2 2p4
Possible Oxidation States -2
Electron Affinity [kJ/mol] 141
Electronegativity [Pauling scale] 3.44
1st Ionization Energy [eV] 13.6181
Year of Discovery 1774
Discoverer Priestley, Joseph & Scheele, Carl Wilhelm
Thermal properties
Melting Point [Celsius scale] -218.4
Boiling Point [Celsius scale] -183
Thermal Conductivity [W/m K] 0.02674
Specific Heat [J/g K] 0.92
Heat of Fusion [kJ/mol] 0.22259
Heat of Vaporization [kJ/mol] 3.4099

## Boron – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Boron is 1.02 J/g K.

Latent Heat of Fusion of Boron is 50.2 kJ/mol.

Latent Heat of Vaporization of Boron is 489.7 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Boron – Properties

Element Boron
Atomic Number 5
Symbol B
Element Category Metalloids
Phase at STP Solid
Atomic Mass [amu] 10.811
Density at STP [g/cm3] 2.46
Electron Configuration [He] 2s2 2p1
Possible Oxidation States +3
Electron Affinity [kJ/mol] 26.7
Electronegativity [Pauling scale] 2.04
1st Ionization Energy [eV] 8.298
Year of Discovery 1808
Discoverer Davy, Sir Humphry & Thénard, Louis-Jaques & Gay-Lussac, Louis-Joseph
Thermal properties
Melting Point [Celsius scale] 2079
Boiling Point [Celsius scale] 2550
Thermal Conductivity [W/m K] 27
Specific Heat [J/g K] 1.02
Heat of Fusion [kJ/mol] 50.2
Heat of Vaporization [kJ/mol] 489.7

## Carbon – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Carbon is 0.71 J/g K.

Latent Heat of Fusion of Carbon is — kJ/mol.

Latent Heat of Vaporization of Carbon is 355.8 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Carbon – Properties

Element Carbon
Atomic Number 6
Symbol C
Element Category Non Metal
Phase at STP Solid
Atomic Mass [amu] 12.0107
Density at STP [g/cm3] 2.26
Electron Configuration [He] 2s2 2p2
Possible Oxidation States +2,4/-4
Electron Affinity [kJ/mol] 153.9
Electronegativity [Pauling scale] 2.55
1st Ionization Energy [eV] 11.2603
Year of Discovery unknown
Discoverer unknown
Thermal properties
Melting Point [Celsius scale] 3367
Boiling Point [Celsius scale] 4827
Thermal Conductivity [W/m K] 129
Specific Heat [J/g K] 0.71
Heat of Fusion [kJ/mol]
Heat of Vaporization [kJ/mol] 355.8

## Lithium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Lithium is 3.6 J/g K.

Latent Heat of Fusion of Lithium is 3 kJ/mol.

Latent Heat of Vaporization of Lithium is 145.92 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Lithium – Properties

Element Lithium
Atomic Number 3
Symbol Li
Element Category Alkali Metal
Phase at STP Solid
Atomic Mass [amu] 6.941
Density at STP [g/cm3] 0.535
Electron Configuration [He] 2s1
Possible Oxidation States +1
Electron Affinity [kJ/mol] 59.6
Electronegativity [Pauling scale] 0.98
1st Ionization Energy [eV] 5.3917
Year of Discovery 1817
Discoverer Arfvedson, Johan August
Thermal properties
Melting Point [Celsius scale] 180.5
Boiling Point [Celsius scale] 1342
Thermal Conductivity [W/m K] 85
Specific Heat [J/g K] 3.6
Heat of Fusion [kJ/mol] 3
Heat of Vaporization [kJ/mol] 145.92

## Beryllium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Beryllium is 1.82 J/g K.

Latent Heat of Fusion of Beryllium is 12.2 kJ/mol.

Latent Heat of Vaporization of Beryllium is 292.4 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Beryllium – Properties

Element Beryllium
Atomic Number 4
Symbol Be
Element Category Alkaline Earth Metal
Phase at STP Solid
Atomic Mass [amu] 9.0122
Density at STP [g/cm3] 1.848
Electron Configuration [He] 2s2
Possible Oxidation States +2
Electron Affinity [kJ/mol]
Electronegativity [Pauling scale] 1.57
1st Ionization Energy [eV] 9.3226
Year of Discovery 1797
Discoverer Vauquelin, Nicholas Louis
Thermal properties
Melting Point [Celsius scale] 1278
Boiling Point [Celsius scale] 2970
Thermal Conductivity [W/m K] 200
Specific Heat [J/g K] 1.82
Heat of Fusion [kJ/mol] 12.2
Heat of Vaporization [kJ/mol] 292.4

## Hydrogen – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Hydrogen is 14.304 J/g K.

Latent Heat of Fusion of Hydrogen is 0.05868 kJ/mol.

Latent Heat of Vaporization of Hydrogen is 0.44936 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Hydrogen – Properties

Element Hydrogen
Atomic Number 1
Symbol H
Element Category Non Metal
Phase at STP Gas
Atomic Mass [amu] 1.0079
Density at STP [g/cm3] 0.0899
Electron Configuration 1s1
Possible Oxidation States +1,-1
Electron Affinity [kJ/mol] 72.8
Electronegativity [Pauling scale] 2.2
1st Ionization Energy [eV] 13.5984
Year of Discovery 1766
Discoverer Cavendish, Henry
Thermal properties
Melting Point [Celsius scale] -259.1
Boiling Point [Celsius scale] -252.9
Thermal Conductivity [W/m K] 0.1805
Specific Heat [J/g K] 14.304
Heat of Fusion [kJ/mol] 0.05868
Heat of Vaporization [kJ/mol] 0.44936

## Helium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization

Specific heat of Helium is 5.193 J/g K.

Latent Heat of Fusion of Helium is — kJ/mol.

Latent Heat of Vaporization of Helium is 0.0845 kJ/mol.

Specific Heat

Specific heat, or specific heat capacity, is a property related to internal energy that is very important in thermodynamics. The intensive properties cv and cp are defined for pure, simple compressible substances as partial derivatives of the internal energy u(T, v) and enthalpy h(T, p), respectively:

where the subscripts v and p denote the variables held fixed during differentiation. The properties cv and cp are referred to as specific heats(or heat capacities) because under certain special conditions, they relate the temperature change of a system to the amount of energy added by heat transfer. Their SI units are J/kg.K or J/mol K.

Different substances are affected to different magnitudes by the addition of heat. When a given amount of heat is added to different substances, their temperatures increase by different amounts.

Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume. Thus the quantity is independent of the size or extent of the sample.

Latent Heat of Vaporization

In general, when a material changes phase from solid to liquid or from liquid to gas, a certain amount of energy is involved in this change of phase. In the case of liquid to gas phase change, this amount of energy is known as the enthalpy of vaporization (symbol ∆Hvap; unit: J), also known as the (latent) heat of vaporization or heat of evaporation. As an example, see the figure, which describes the phase transitions of water.

Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent Heat of Fusion

In the case of solid to liquid phase change, the change in enthalpy required to change its state is known as the enthalpy of fusion (symbol ∆Hfus; unit: J), also known as the (latent) heat of fusion. Latent heat is the amount of heat added to or removed from a substance to produce a phase change. This energy breaks down the attractive intermolecular forces and must provide the energy necessary to expand the system (the pΔV work).

The liquid phase has higher internal energy than the solid phase. This means energy must be supplied to a solid to melt it. Energy is released from a liquid when it freezes because the molecules in the liquid experience weaker intermolecular forces and have higher potential energy (a kind of bond-dissociation energy for intermolecular forces).

The temperature at which the phase transition occurs is the melting point.

When latent heat is added, no temperature change occurs. The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless otherwise specified.

## Helium – Properties

Element Helium
Atomic Number 2
Symbol He
Element Category Noble Gas
Phase at STP Gas
Atomic Mass [amu] 4.0026
Density at STP [g/cm3] 0.1785
Electron Configuration 1s2
Possible Oxidation States 0
Electron Affinity [kJ/mol]
Electronegativity [Pauling scale]
1st Ionization Energy [eV] 24.5874
Year of Discovery 1895
Discoverer Ramsey, Sir William & Cleve, Per Teodor
Thermal properties
Melting Point [Celsius scale] -272.2
Boiling Point [Celsius scale] -268.9
Thermal Conductivity [W/m K] 0.1513
Specific Heat [J/g K] 5.193
Heat of Fusion [kJ/mol]
Heat of Vaporization [kJ/mol] 0.0845