Science Yr8

Question 1

Diffusion

Answer 1

Particles in a liquid or gas spread out from an area of high concentration to an area of low concentration.

Question 2

What do alkalis release into a solution?

Answer 2

Hydroxide ions

Question 3

What do acids release into a solution?

Answer 3

Hydrogen ions

Question 4

Neutralisation

Answer 4

Acid+alkali

Question 5

Carbohydrate

Answer 5

The body’s main source of energy

Question 6

Lipids

Answer 6

Source of energy, protect organs from damage

Question 7

Protein

Answer 7

Used to build tissue for growth and repair

Question 8

Fibre

Answer 8

Aids digestion, helps food move through the digestion

Question 9

What does smoking damage?

Answer 9

The cilia and stops moving mucus out of lungs resulting in lung infections and a persistent cough.

Question 10

What stimulant makes smoking addictive?

Answer 10

Nicotine

Question 11

Complete combustion

Answer 11

When there is enough oxygen to oxidise the fuel

Question 12

Incomplete combustion

Answer 12

When there is limited oxygen and it partially oxidises the fuel resulting in carbon monoxide

Question 13

Hooke’s law states that the extension of a piece of material doubles, when the …

Answer 13

Force doubles

Question 14

Moment=

Answer 14

Force x perpendicular distance from pivot

Question 15

Gas pressure

Answer 15

The force exerted over a certain area by a gas measured in newton’s per metre squared.

Question 16

Atmospheric pressure

Answer 16

Pressure caused by the collisions of air molecules that produce a force on an area

Question 17

Element

Answer 17

A substance made up of only one type of atom

Question 18

Compound

Answer 18

Combination of two or more different elements- chemically combined

Question 19

Mixture

Answer 19

Atoms grouped together but not chemically bonded

Question 20

Molecule

Answer 20

Two or more atoms chemically combined

Question 21

Independent variable

Answer 21

The element you change in an experiment

Question 22

Dependent variable

Answer 22

The part of the experiment you measure

Question 23

Control variable

Answer 23

The part of an experiment you keep the same.

Question 24

What is resistance measure in?

Answer 24

Ohms

Question 25

Resistance=

Answer 25

Potential difference÷current

Question 26

What are the four main functions of the skeleton?

Answer 26

Support the body Protect vital organs Help the body move Make blood cells

Question 27

What does bone marrow produce?

Answer 27

Red and white blood cells

Question 28

Atom

Answer 28

Smallest part of an element that can exist

Question 29

Decomposition

Answer 29

When a compound breaks down into simpler compounds or elements

Question 30

Thermal decomposition

Answer 30

When a substance breaks down upon heating

Question 31

Salt

Answer 31

Compound formed when an acid reacts with a metal element or compound

Question 32

Amplitude

Answer 32

Height of wave measure from the middle to the top or bottom

Question 33

Frequency

Answer 33

The number of waves on an oscilloscope per second

Question 34

Wavelength

Answer 34

The distance from one point on a wav to the same point on the next wave

Question 35

Angle of incidence=

Answer 35

Angle of reflection

Question 36

Constructive interference

Answer 36

Waves join together and get bigger

Question 38

Destructive interference

Answer 38

When waves cancel each other out

Question 39

Ultra sound

Answer 39

Sound above 20,000 Hz

Question 40

Infra sound

Answer 40

Sound below 20Hz

Question 41

If an object is balanced

Answer 41

Sum of anticlockwise moments=sum of clockwise moments

Question 42

Joint

Answer 42

A place where two or more bones meet

Question 43

Ligament

Answer 43

Connects bone to bone

Question 44

Tendon

Answer 44

Connects muscle to bone

Question 45

Hinge joint

Answer 45

Only allows forward and backward movement eg leg

Question 46

Pivot joint

Answer 46

When a joint move in one direction