Why is it difficult for hydrogen atoms to stick together

So, the energy of two hydrogen atoms is lower when the two atoms are together than when the two atoms are apart; that is why they stay together.

Explanation:

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.