Question

What is the lightest element on earth?

Answer 1

Lightest element on earth:

• Hydrogen is the simplest and lightest element and the most common in the entire universe.
• The atomic number and mass number both are unity for hydrogen.
• Atomic symbol of hydrogen:

${}_1{}^1\mathrm{H}$

• Since the hydrogen atom has only 1 electron and 1 proton, the total mass of hydrogen is the smallest.
• Thus, hydrogen is the lightest element.