Question

Which substance can be broken down by chemical means

Answer 1

Answer: Option (1) is the correct answer.

Explanation:

A compound is defined as the substance in which different elements are chemically combine together in a fixed ratio by mass.

For example, chemical formula of ammonia is $NH_{3}$.

Here, in $NH_{3}$ the atoms are present in 1:3 ratio.

A compound can be divided into its constituent or simpler substances by chemical means.

On the other hand, an element is defined as a substance which contains atoms of only one type.

For example, Al, Sb, Ar etc are all elements.

An element can never be divided into its constituent parts.

Thus, we can conclude that out of the given options ammonia is the substance which can be broken down by chemical means.

Answer 2

Answer:

1. Ammonia  

Step-by-step explanation:

Ammonia, NH₃, is a compound of nitrogen and hydrogen.

Thus, it can be broken down by chemical means into the elements nitrogen and hydrogen.

The other options are wrong, because Al, Sb, and Pb are elements. They cannot be broken down chemically into simpler substances.