Which can be determined using a chemical formula?
a. the elements that make up the compound
b. the substances that make up a solution
c. the ph of a solution
d. the boiling point of a compound

a. the elements that make up the compound

Explanation:

Chemical formulas are the symbolic representation of the elements contained in a compound along with their relative proportions.

For example: The chemical formula for water is which shows that it is formed by combination of hydrogen and oxygen in the ratio of 2: 1 respectively.

pH of the solution is determined by litmus paper, pH paper or pH meter.

Boiling point is the temperature at which atmospheric pressure becomes equal to the atmospheric pressure.

- 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