Write three physical properties of hydrogen. 

State three chemical properties of hydrogen. 

Write down an equation in which hydrogen reduces metal oxides to their respective metals. 

Hydrogen is the lightest gas. Explain with the help of an experiment. 

What are ionic hydrides? 

How is hydrogen prepared in the laboratory? Explain with the help of a labelled diagram. 

Complete and balance the following equation:

$\mathrm{Ca}+{\mathrm{H}}_2\mathrm{O}\to$