Definitions

Question 1

Law of Conservation of Energy

Answer 1

The law of conservation of energy states that energy cannot be created or destroyed, and can only be converted from one form to another.

Question 2

Newton’s First Law of Motion

Answer 2

Newton’s first law of motion states that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.

Question 3

Radiation

Answer 3

the process by which thermal energy is transferred by electromagnetic waves

Question 4

Convection

Answer 4

the process by which thermal energy is transmitted from one place to another by the movement of heated gas or liquid

Question 5

Conduction

Answer 5

the transfer of thermal energy through a material without the obvious movement of the medium itself

Question 6

Kinetic Particle Theory

Answer 6

The metal particles gain thermal energy from the heat source and vibrate more vigorously. They collide with neighbouring particles more frequently, transferring energy during the collisions. This in turn causes the latter to gain kinetic energy. Additionally, metals have free moving electrons which move rapidly and collide with neighbouring particles and electrons, thus transferring more energy during collisions

Question 7

Temperature

Answer 7

the measure of the average kinetic energy of molecules in a body

Question 8

Thermal energy

Answer 8

the energy in a body due to its temperature

Question 9

Chemical change

Answer 9

Is a process by which new substance(s) of different chemical properties are formed

Question 10

Combustion

Answer 10

Involves the burning of a substance in the presence of oxygen to form new compound(s).

Question 11

Oxidation

Answer 11

the addition of oxygen to a substance.

Question 12

Decomposition

Answer 12

Involves the breakdown of a compound into simpler substances

Question 13

Precipitation

Answer 13

Involves the formation of a solid when two solutions are mixed

Question 14

Respiration

Answer 14

Process by which cells in living organisms get energy

Question 15

Photosynthesis

Answer 15

Process by which green plants transform light energy into chemical energy

Question 16

Chemical Bonding

Answer 16

the electrostatic force of attraction between particles/sub-atomic particles

Question 17

Ionic Bonding

Answer 17

the electrostatic force of attraction between oppositely charged ions

Question 18

Covalent Bonding

Answer 18

the electrostatic force of attraction between the shared pair of electrons and the positive nuclei of the two atoms

Question 19

Law of Conservation of Mass

Answer 19

Atoms are not created or destroyed in a reaction - they are only rearranged. Mass is conserved

Question 20

Habitat

Answer 20

a place where organisms live

Question 21

Population

Answer 21

Organisms of the same kind that live in a particular habitat

Question 22

Community

Answer 22

Made up of the different plant and animal populations living together and interacting in a habitat

Question 23

Ecosystem

Answer 23

The interactions between a community and its physical environment make up an environment

Question 24

Carbon Sinks

Answer 24

areas that store carbon from the atmosphere for a long period of time. They store more carbon than they release

Question 25

Electric Current

Answer 25

The rate of flow of electrons in a circuit

Question 26

Electromotive force (e.m.f.)

Answer 26

the work done by the source in driving a unit charge around a complete circuit

Question 27

Potential Difference

Answer 27

the work done to drive a unit charge across an electrical component

Question 28

Resistance

Answer 28

The resistance of a component is the ratio of the potential difference across it to the current flowing through it

Question 29

Electric power

Answer 29

the amount of electrical energy it converts to other forms of energy in one second

Question 30

Digestion

Answer 30

the breaking down of large, insoluble food molecules into smaller, soluble molecules that can be absorbed by the body

Question 31

Physical digestion

Answer 31

A mechanical/physical breakdown of large pieces of food into smaller pieces

Question 32

Chemical Digestion

Answer 32

A process whereby large and complex substances are broken down into smaller and simpler substances by the action of enzymes

Question 33

Enzymes

Answer 33

complex proteins that speed up the rate of chemical reactions

Question 34

Diffusion

Answer 34

The net movement of particles from a region where they are of higher concentration to a region where they are of lower concentration

Question 35

Arteries

Answer 35

Arteries are blood vessels that carry oxygenated blood away from the heart to supply the body’s tissues and organs.

Question 36

Veins

Answer 36

Veins are blood vessels that transport deoxygenated blood from the body’s tissues back to the heart.

Question 37

Capillaries

Answer 37

a fine network of tiny tubes linking arterioles and venules and they allow exchange of materials between blood and tissue

Question 38

Osmosis

Answer 38

the net movement of water molecules from water molecules from a solution of higher water potential to a solution of lower water potential, through a selectively permeable membrane

Question 39

Fertilisation

Answer 39

the fusion of the nucleus of a male gamete and the nucleus of a female gamete to form a zygote

Question 40

Mensuration

Answer 40

the process in which the uterine lining begins to break down and flow out of the body

Question 41

Resultant Force

Answer 41

The total force after considering all forces acting on a body

Question 42

Kilowatt-hour

Answer 42

The amount of electrical energy consumed by a 1kW appliance in an hour consumed by kilowatt appliances

Question 43

Electrocution

Answer 43

It occurs when a person is injured or killed by a large current passing through the body

Question 44

Short circuit

Answer 44

When the live wire touches the neutral wire, providing a shorter path of low resistance for the current to flow through