IGCSE Chemisty - Topic 1

Question 1

What’s an atom?

Answer 1

The smallest particle of an element

Question 2

Proton Mass

Answer 2

1 amu

Question 3

Neutron Mass

Answer 3

1 amu

Question 4

Electron Mass

Answer 4

1/1837 (Approx 0 amu)

Question 5

Proton Charge

Answer 5

+1 (Positive Charge)

Question 6

Neutron Charge

Answer 6

0

Question 7

Electron Charge

Answer 7

-1 (Negative Charge)

Question 8

Atomic Number

Answer 8

The number of protons in the nucleus of the atom

Question 9

Mass number

Answer 9

The total number of protons and neutrons in the nucleus of the atom

Question 10

Isotopes

Answer 10

Atoms of the same element with the same number of protons but a different number of neutrons

Question 11

Element

Answer 11

A pure substance made of only one kind of atom

Question 12

Chromatography

Answer 12

A technique that is used to separate components of a mixture

Question 13

Solute

Answer 13

The substance which dissolves in a liquid to form a solution

Question 14

Soluble

Answer 14

Describes a substance that will dissolve

Question 15

Solvent

Answer 15

The liquid in which a solute dissolves in

Question 16

Solution

Answer 16

The mixture formed when a solute is dissolved in a solvent

Question 17

In-soluble

Answer 17

Describes a substance that will not dissolve

Question 18

Solubility

Answer 18

Describes the ability/likelihood of a solute to dissolve in a solvent

Question 19

Brownian motion

Answer 19

The random movement of particles in liquids and gases

Question 20

What are the two types of isotopes?

Answer 20

Radioactive (Unstable) and Non-radioactive (Stable

Question 21

Compounds

Answer 21

A substance made up of atoms of two or more different chemically combined elements

Question 22

Mixture

Answer 22

A combination of two or more substances that are not chemically combined

Question 23

Alloy

Answer 23

An alloy is a mixture of two or more elements, where at least one element is a metal.

Question 24

Ions

Answer 24

Atoms or groups of atoms with a positive or negative charge

Question 25

Diffusion

Answer 25

Movement of particles from an area of higher concentration to an area of lower concentration

Question 26

Formula for Rf (Reference front) value

Answer 26

Distance travelled by substance/distance travelled by solvent

Question 27

Describe Solid

Answer 27

Close together and touching, regular arrangement (lattice), fixed shape and volume, can not freely move but does vibrate, can not be compressed and does not diffuse

Question 28

Describe Liquid

Answer 28

Touching, irregular arrangement, can freely move/slide over each other, force of attraction holds them together, fixed volume but no fixed shape, can not be compressed, slow diffusion

Question 29

Describe Gas

Answer 29

Far apart, irregular, can freely move in a random and independent manner, very small or no force of attraction, no fixed shape, no fixed volume but can fit in a container, easily compressed, rapid diffusion