What kind of group 1 atoms are the most reactive?
a. small atoms
c. atoms with the most electrons in the valence level
b. large atoms
d. atoms at the top of the periodic table

- B, Large atoms.

Explanations:- An element is highly reactive if it could easily loses electron from it's outer most shell.

It's easy for an atom to lose the electron from it's outer most shell if it's size is bigger means the electron is farther from the nucleus. The distance of an electron from it's nucleus increases as we move down in a group as the new shells are being added.

So, the elements become larger as we move down in a group and so it's easy for them to lose the electron from their outer most shell and so they are move reactive.

For example, K is more reactive than Na as K is below Na in the periodic table.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

they are all solids.