Ammonia is a weak base because

it produces few hydroxide ions in water

it cannot hold on to its hydroxide ions

it is only slightly soluble in water

it is a dilute solution

I think it's the 1 st answer

Explanation:

Ammonia is a weak base because its nitrogen atom has an electron pair that readily accepts a proton. Also, when dissolved in water, ammonia acquires hydrogen ions from water to produce hydroxide and ammonium ions. It is the production of these hydroxide ions that imparts ammonia its characteristic basicity.

- 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