Chemistry - An Introduction

Question 1

What is the smallest unit of matter?

Answer 1

Atoms are the smallest unit of matter.

Question 2

What is an element?

Answer 2

An element is a pure substance that contains only one type of atom.

Question 3

What is a pure substance?

Answer 3

A pure substance is a substance that cannot be broken down into simpler forms. It is only composed one type of particle, including molecules, compounds or atoms.

Question 4

Who proposed the concept of an atom?

Answer 4

A Greek philosopher named Democritus, proposed the concept of an atom.

Question 5

How long ago was the concept of an atom first proposed?

Answer 5

The concept of an atom was proposed over 2500 years ago.

Question 6

In what shape is an atom modelled as?

Answer 6

An atom is modelled in the shape of a sphere.

Question 7

What are the smaller particles that make up an atom?

Answer 7

The smaller particles which make an atom are called subatomic particles.

Question 8

How many subatomic particles are there in an atom?

Answer 8

There are three subatomic particles.

Question 9

What subatomic particle has a positive charge?

Answer 9

The protons have a positive charge.

Question 10

What subatomic particle has a neutral charge?

Answer 10

The neutrons have a neutral charge.

Question 11

What subatomic particle has a negative charge?

Answer 11

The electrons have a negative charge.

Question 12

Name the three subatomic particles.

Answer 12

Protons (+), neutrons (=) and electrons (–)

Question 13

What is the structure of an atom?

Answer 13

The atom contains a nucleus found in the centre of the atom and shells in which the electrons “orbit” around.

Question 14

What is the nucleus and what does it contain?

Answer 14

The nucleus is found at the centre of an atom. It contains the protons (positive charge) and the neutrons (neutral charge). These subatomic particles found in the nucleus can also be called nucleons .

Question 15

What are the nucleons?

Answer 15

The nucleons refers to the internal content that is found in the nucleus, which contain the protons and neutrons.

Question 16

What is the proton?

Answer 16

The proton is one of three subatomic particles found in an atom. It holds a positive charge and has nearly the equivalent mass of the neutron. It is also found in the nucleus of the atom.

Question 17

What is the neutron?

Answer 17

The neutron is one of three subatomic particles found in the atom. It holds no charge (neutral) and nearly has the equivalent mass of the proton. It is also found in the nucleus of the atom.

Question 18

What is the electron?

Answer 18

The electron is the smallest of the three subatomic particles. They hold a negative charge, and are responsible for orbiting around the nucleus from a far distance.

Question 19

What overall charge do atoms have?

Answer 19

Atoms have an overall neutral charge.

Question 20

Why do atoms have a neutral charge overall?

Answer 20

Atoms always have the same number of protons and electrons, which balance out the charge. As a result, this causes for no charge that is held by the atom.

Question 21

What is a shell of an atom?

Answer 21

The shell is the space in which the electrons orbit around the nucleus from a far distance.

Question 22

What part of the atom has the strongest influence on the properties and mass of an atom?

Answer 22

The nucleus contains the protons and neutrons, which are the heaviest subatomic particles in the atom. As a result, their great mass is responsible for majority of the atoms properties, features and mass.

Question 23

How are there different types of atoms?

Answer 23

Different atoms are formed by different combinations of the number of protons, electrons and neutrons. Each subatomic particle, especially the proton and neutron, have the greatest influence on the different properties found in each atom.

Question 24

Provide an example of an element.

Answer 24

Gold (Au) is an elemental substance, as its internal content only contains gold atoms.

Question 25

What is a monatomic substance?

Answer 25

A monatomic substance is where the particles of one certain substance is just solely an atom itself. For example, helium. The particles of a helium consist of only a single atom.

Question 26

What is a molecule?

Answer 26

A molecule is when two or more atoms chemically bond together. For example, an oxygen molecule.

Question 27

What is a molecular compound?

Answer 27

A compound in when two more different types of atoms chemically bond together. For example, a water molecular compound.

Question 28

What is a lattice?

Answer 28

A lattice is a three dimensional framework or structure of different atoms or molecules. For example, table salt. Table salt involves the framework of sodium and chlorine atoms.

Question 29

What is atomic number?

Answer 29

Atomic number refers to the number of protons found in the nucleus of an atom.

Question 30

What is atomic mass?

Answer 30

Atomic mass refers