Review the electron configurations of the elements in group 2, moving down from beryllium (Be) to radium (Ra). What do you observe?
Select the correct answer.
O Moving down the group, each element has one more electron in its highest s sublevel than the element above it.
Each element's electron configuration has a noble gas core with two electrons in the next s sublevel.
Moving down the group, each element has two more electrons than the element that comes above it.
The electron configuration of radium does not follow the pattern of the other elements in group 2.

- 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