Question

Which substance can be decomposed by chemical means?

Answer 1

The substance that can be decomposed by chemical means is $\boxed{{\text{c}}{\text{. methane}}}$.

Further Explanation:

The pure form of matter is called substance whereas the combination of atoms and molecules is known as mixture.

Substance is further divided into two types:

1. Element

It is a type of pure substance and is the simplest form that cannot be broken down by any chemical means. Copper, iron, and cobalt are some of the examples of elements.

2. Compound

It is composed of two or more different elements that are held together by chemical bonds. These can be broken down into their respective constituents. Their properties are quite different from those of their constituent elements. NaCl, ${\text{C}}{{\text{O}}_{\text{2}}}$ and ${{\text{H}}_{\text{2}}}{\text{O}}$ are examples of compounds.

a. Cobalt is an element so it is the simplest form in which it can exist. Therefore it cannot be broken down or decomposed by chemical methods.

b. Krypton is an element so it is the simplest form in which it can exist. Therefore it cannot be broken down or decomposed by chemical methods.

c. Methane is formed from one carbon and four hydrogen atoms so it is a compound. Since compounds can be decomposed chemically, methane is also decomposed by chemical means.

d. Zirconium is an element so it is the simplest form in which it can exist. Therefore it cannot be broken down or decomposed by chemical methods.

Learn more:

1. Which sample is a pure substance? brainly.com/question/2227438

2. Which is a characteristic of a mixture? brainly.com/question/1917079

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Elements, compounds, and mixtures

Keywords: substance, methane, cobalt, zirconium, krypton, element, compound, chemical means, decomposed, broken down, simplest form.

Answer 2

Methane, answer c, can be decomposed by chemical means because methane is a compound. Methane is made up of one atom of carbon and four atoms of hydrogen. Compounds can be broken down. Cobalt, krypton, and zirconium are all elements, and elements cannot be chemically decomposed.