Question

Which of the following substances has only one type of atom? A. Water B. Salt C. Sand D. Oxygen

Answer 1

`D.`

Explanation:

Oxygen is the answer, as it is an element, and therefore has only one type of atom, which is the oxygen atom of course!

Water has a chemical formula of `H_2O`, so it cannot be composed of only one type of atom, as it contains both hydrogen and oxygen atoms.

Table salt has a chemical formula of `NaCl`. As with water, it is also composed of two types of atoms, sodium `(Na)` and chlorine `(Cl)` atoms. Even if you talk about salts made in a neutralization reaction, they are still composed of `2` or more substances.

Sand is a mixture and therefore does not have a chemical formula. If it's a mixture, it is definitely composed of two or more different substances and atoms.

So, our final answer is `D.` oxygen.