Question

A pure substance which contains only one type of atoms is called (1) an clement (2) a compound (3) a solid (4) a liquid

Short answer

(1) an element

Step-by-step solution

- Understand the Question

The question asks us to identify the type of pure substance that contains only one type of atoms from the given options.

- Review the Options

Examine each option carefully: (1) an element (2) a compound (3) a solid (4) a liquid

- Analyze Option 1 - Element

An element is a pure substance that is made of only one type of atom. For example, gold (Au) or oxygen (O).

- Analyze Option 2 - Compound

A compound is a substance formed from two or more types of atoms chemically bonded together. For example, water (H₂O) or carbon dioxide (CO₂).

- Analyze Option 3 - Solid

A solid refers to the state of matter. It can be either an element, a compound, or a mixture.

- Analyze Option 4 - Liquid

A liquid also refers to the state of matter and can be an element, a compound, or a mixture.

- Choose the Correct Answer

Based on the analyses, the only correct answer is 'an element' since it is the only option that refers specifically to a pure substance containing only one type of atom.

Key concepts

element

An element is a pure substance that is made up of only one type of atom. Each element is unique and has its own specific properties.
For example:

• Gold (Au)
• Oxygen (O)

Elements are the building blocks of all matter. In the periodic table, each element is listed with its unique atomic number which represents the number of protons in its nucleus. Pure elements cannot be broken down into simpler substances by chemical means.

compound

A compound is a pure substance that consists of two or more different types of atoms chemically bonded together. This chemical bonding creates a substance with unique properties that are different from the properties of the individual elements that comprise it.
For example:

• Water (H₂O)
• Carbon dioxide (CO₂)

Compounds can only be separated into their component elements through chemical reactions. This distinction makes compounds different from mixtures, where the components can be physically separated.

state of matter

The state of matter describes the physical form in which a substance exists. The three common states of matter are:

• Solid
• Liquid
• Gas

In solids, particles are tightly packed together in a fixed arrangement, giving them a definite shape and volume.
In liquids, particles are close together but not in a fixed position, allowing liquids to flow and take the shape of their container while maintaining a definite volume.
In gases, particles are far apart and move freely, allowing gases to fill any container completely and take on both its shape and volume. States of matter can change through physical processes such as melting, freezing, condensation, and evaporation.

atom

An atom is the smallest unit of an element that retains the properties of that element. It consists of a nucleus, containing protons and neutrons, surrounded by electrons that orbit the nucleus.
Here are some key points about atoms:

• Protons are positively charged particles found in the nucleus.
• Neutrons are neutral particles also located in the nucleus.
• Electrons are negatively charged particles that orbit the nucleus in various energy levels.

The number of protons in the nucleus determines the element's identity and its position on the periodic table. Atoms can combine with other atoms to form molecules, which are the foundation of compounds. Understanding atoms is fundamental to the study of chemistry and the composition of matter.