Chapter 1 2 3 4 - Basic Chemistry

Question 0

Definition of an Atom

Answer 0

The smallest part of any element which can take part in a chemical reaction

Question 1

Define an element

Answer 1

An element is a substance which can not be divided into simpler substances by chemical means

Question 2

Definition of a molecule

Answer 2

The smallest part of any element or compound which can exist independently

Eg - H2

Question 3

Definition of a compound

Answer 3

A compound is formed when two or more elements combined chemically

Eg - H2O

Question 4

What is a mixture

Answer 4

Two or more substances are mixed together but do not combine chemically

Eg - air

Question 5

Define atomic number

Answer 5

The number of protons present in the nucleus of an atom of an element

Question 6

Define mass number

Answer 6

The number of protons and neutrons present in the nucleus of an atom of an element

Question 7

Definition of an isotope

Answer 7

Isotopes are atoms of the same element which have the same atomic number but different mass numbers. They have the same number of protons but different number of neutrons.

Question 8

What is the Octet Rule

Answer 8

Atoms gain share or lose electrons in order to have eight electrons in their outside shell.

Question 9

Definitions of an Ion

Answer 9

Ions are atoms which have either lost or gained electrons, and so have become either positively or negatively charged.

Question 10

Historial Development of Atomic Theory

1) Dalton

Answer 10

All matter is made up of very small particles called atoms. All atoms are indivisible and cannot be broken down into simpler particles. Atoms cannot be created or destroyed.