Definitions

Question 1

Ph

Answer 1

A scale to measure how acidic or basic a liquid is. pH is a number from 0 to 14.

Question 2

Indicator

Answer 2

An indicator is a dye or chemical that changes colour in the presence of an acid or base, and can therefore indicate or show whether a substance is an acid, base or neutral.

Question 3

Periodicity or periodic table trends

Answer 3

Arranging elements according to their similar properties

Question 4

Element

Answer 4

Is a pure substance that cannot be broken into smaller units or parts

Question 5

Valency

Answer 5

The number of bonds formed by an atom of an element

Question 6

Atoms

Answer 6

Consists of a small, dense nucleus in the centre and a nuclei consists of two types of particles, protons +, and neutrons (neutral)

Question 7

Mass number

Answer 7

The number of protons and neutrons in a nucleus

Question 8

Compound

Answer 8

A pure substance that consists of two or more elements that have chemically combined

Question 9

Molecule

Answer 9

Defined as two or more atoms that have chemically bonded with each other in a fixed ratio

Question 10

Diatomic molecule

Answer 10

Some non-metals (r.h.s of Periodic Table) are gases at room temperature that exist as molecules that are made up of two atoms each

Question 11

Neutralisation reaction

Answer 11

When an acid and a base combine, they react together. This makes the acid less acidic but more neutral

Question 12

Force

Answer 12

A push or pull of an object

Question 13

Spring balance

Answer 13

A simple device consisting of a spring which when stretched gives a reading of the force used to stretch the spring

Question 14

Free-body diagram

Answer 14

Using a circle to represent the object and the different length arrows to represent forces acting on the object

Question 15

Contact force

Answer 15

Is exerted when two objects are in contact, that is, they touch each other

Question 16

Friction

Answer 16

A contact force that a surface exerts on an object

Question 17

Tension

Answer 17

Is a contact force in a rope/cable that is used to carry a load

Question 18

Compression

Answer 18

Is contact force that squeezes/pushes something into a smaller space

Question 19

Non-contact force

Answer 19

Or a field force, acts over a distance. The two bodies exert field forces on each other without touching each other

Question 20

Weight/Fgravity

Answer 20

Any object that has mass experiences a gravitational force. Always exerted downwards towards the centre of the earth

Question 21

Body mass

Answer 21

The measure of the amount of matter that it is made of

Question 22

Magnetic force

Answer 22

A force that two magnetic objects exert on each other over a distance

Question 23

Resultant/Net force

Answer 23

The single force that replaces all other forces. The sum of all the force acting on the object

Question 24

Drag

Answer 24

Solid moving through a fluid substance; water, air etc.

Question 25

Work

Answer 25

The process of transferring energy from one object/system to another/converting energy from one form to another

Question 26

Work is done on an object

Answer 26

When a force acts upon an object to cause a displacement of the object in the direction of the force

Question 27

Power

Answer 27

The rate at which work is done

Question 28

Energy

Answer 28

The ability to do work

Question 29

Kinetic energy

Answer 29

The energy an object possess due to its motion

Question 30

Gravitational potential energy

Answer 30

The energy an object possesses due to its position above the ground

Question 31

Mechanical energy

Answer 31

The energy that is possessed by an object due to its motion or its position

Question 32

Electric current

Answer 32

Rate of flow of charge

Question 33

Electron flow

Answer 33

Flow of negative charge from the negative to the positive terminal of a cell/battery

Question 34

Conventional current

Answer 34

The flow of positive charge from the positive to the negative terminal of a cell/battery

Question 35

Resistance

Answer 35

Opposition to the flow of charge

Question 36

Short circuit

Answer 36

Happens when another, easier path is accidentally made in an electric circuit

Question 37

Electromagnet

Answer 37

A coil of wire wrapped around a soft iron core connected to a power source

Question 38

Electrolysis

Answer 38

A chemical reaction that takes place due to an electric current flowing through a conducting solution

Question 39

Ammeter

Answer 39

Measuring device used to measure the electric current in the circuit

Question 40

Voltmeter

Answer 40

Instrument used to measure potential difference

Question 41

Potential difference

Answer 41

The work done per unit positive charge

Question 42

Rheostat

Answer 42

An apparatus that varies resistance, increase/decrease current

Question 43

Ohmic resistor

Answer 43

Obeys Ohm’s law where the ratio V/I is constant

Question 44

Non-Ohmic resistor

Answer 44

One that does not obey Ohm’s Law and where the ratio V/I is not constant

Question 45

Variable resistor

Answer 45

Resistors where we can adjust the resistance ourselves

Question 46

Law of conservation of matter

Answer 46

Matter is neither created nor destroyed, so we must have the same number and kind of atoms after the chemical change as were present before the chemical change

Question 47

Combustion

Answer 47

Process where some metals react with oxygen

Question 48

Metal oxide

Answer 48

The product when metals are burnt in the air containing oxygen

Question 49

Rust

Answer 49

A complex compound formed when iron in a metal reacts with oxygen

Question 50

Galvanising

Answer 50

Process of applying a protective zinc coating to steel/iron to prevent rusting

Question 51

Electroplating

Answer 51

Makes use of electrolysis, whereby an electric current is passed through an electrolyte and one metals deposited onto another

Question 52

Sacrificial anode

Answer 52

Works by oxidising more quickly than the metal it is protecting

Question 53

Non-metal oxide

Answer 53

Formed when you burn a non-metal in air, the non-metal reacts with the oxygen in the air

Question 54

Decomposition

Answer 54

A reaction in which a compound splits up into two or more simpler substances. AB ➡️ A + B

Question 55

Endothermic reaction

Answer 55

A reaction that the system absorbs energy from its surroundings in the from of heat

Question 56

Exothermic reaction

Answer 56

A reaction that releases energy from the system in the form of heat

Question 57

Electrolytic cell

Answer 57

When a solution of copper (II) chloride is placed in a beaker together with two carbon electrodes connected to a power source.

Question 58

Synthesis reaction

Answer 58

The reverse of decomposition of a compound into elements. Elements that can react with each other to form a new substance - a compound