Question

Calcium carbonate is a compound that is used to make chalk for drawing on rocks or pavement. One molecule has one atom of calcium (Ca), one atom of carbon (C), and three atoms of oxygen (O). Which is the correct way to write the chemical formula for calcium carbonate?

3CaCO
Ca3CO
CaCO3
Ca3C3O3

Answer 1

The correct answer is C) CaCO3, here's why:
1. So, one molecule has only one atom of calcium, which is: (Ca)⇒1 Ca
2. Then there are one atom of carbon: (C) ⇒1 C
3. Finally, there are three atoms of oxygen: (O) ⇒ O3

Good luck with your studies, I hope this helps~!

Answer 2

Answer:
`CaCO_3`

Explanation:-

A compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Here calcium is having an oxidation state of +2 and carbonate is a polyatomic ion with oxidation state of -2. Thus they combine to form neutral
`CaCO_3`.

The chemical formula of an ionic compound is written as
`CaCO_3`.