Methane, oxygen, carbon dioxide and water are the four substances.
oxygen
Ammonium nitrate leaves no residue when heated:NH4NO3 Δ→ N2O + 2H2O
It i scalled insulator. The substance do not allow heat to pass through it It Is also heat resistant (dont let heat through it). An example of a heat resistant material is wood.
An insulator is the name of this substance.
CaSO4 2H2O
The energy needed to change a substance from a liquid to a gas is called the enthalpy (or heat) of vaporization.
The heat energy required to change a substance between solid & liquid at constant temperature is called the "latent heat of fusion". If the change is from solid to liquid the substance gains this energy. If the change is from liquid to solid the substance gives up this energy. The exact amount of latent heat of fusion is different for different substances.
Hydrogen peroxide ... but its written as H2O2.
Two molecules of water.
sodium nitrite
photosynthesis (leaving out intermediate steps) 6CO2 + 6H2O + h*nu -> C6H12O6 + 6O2 reaction of metallic sodium with water: 2Na + 2H2O -> 2NaOH + H2 + heat
Calcium sulphate hemihydrate, CaSO4.1/2H2O