Chemistry

Question 1

Alkali

Answer 1

A base that dissolves in water

Question 2

Alkaline solution

Answer 2

A solution made of a base/alkali and water

Question 3

Allotrope

Answer 3

Different forms of the same element

Question 4

Base

Answer 4

A substance that releases hydroxide ions

Question 5

Acid

Answer 5

A substance that releases hydrogen ions into an aqueous solution

Question 6

Indicator

Answer 6

A chemical that changes colour to show whether a substance is acidic, basic or neutral

Question 7

What colour does litmus paper turn when dipped into a base?

Answer 7

Blue, b or base and b or blue

Question 8

What colour does litmus paper turn when dipped into an acid

Answer 8

Red

Question 9

Cation

Answer 9

An ion that has fewer electrons than protons, making it positively charged

Question 10

Anion

Answer 10

An ion with more electrons than protons, making it negatively charged

Question 11

pH

Answer 11

A scale used to measure the concentration of H+ ions in a substance

Question 12

Hydrogen ion

Answer 12

H+, released by acids

Question 13

Hydroxide ion

Answer 13

OH- , released by bases

Question 14

Aerobic respiration

Answer 14

Respiration that uses oxygen as a reactant to change glucose into energy

Question 15

Alveoli

Answer 15

Microscopic air sacs in the lungs that allow oxygen to enter the bloodstream and carbon dioxide to be removed from the bloodstream

Question 16

Anaerobic respiration

Answer 16

Respiration that does not require oxygen to convert glucose into energy

Question 17

Antacids

Answer 17

Tablets or liquid used to relieve heart burn

Question 18

Chloroplast

Answer 18

Organelle in a plant cell that contains chlorophyll, where photosynthesis happens

Question 19

Combustion

Answer 19

A rapid reaction with oxygen, that produces energy in the form of heat or light

Question 20

Complete combustion

Answer 20

Combustion that occurs when there is unlimited amount of oxygen available, it produces carbon dioxide and water vapour

Question 21

Incomplete combustion

Answer 21

Combustion that occurs when there is a limited amount of oxygen available, produces carbon and carbon monoxide

Question 22

Endothermic reaction

Answer 22

Reaction that absorbs energy

Question 23

Exothermic reaction

Answer 23

Reaction that gives off energy

Question 24

Enzyme

Answer 24

A chemical that helps a chemical reaction, but is not used up in the reaction

Question 25

Glucose

Answer 25

A simple sugar, product of photosynthesis and reactant of respiration, C6H12O6

Question 26

Chlorophyll

Answer 26

A green chemical found the chloroplast of a green plant, traps suns energy for photosynthesis

Question 27

Chemical digestion

Answer 27

The process that breaks down large molecules in food into smaller ones that can be absorbed by the body

Question 28

Carbon sink

Answer 28

Materials that store carbon in their structures, eg plants and animals

Question 29

Mitochondria

Answer 29

Organelles in plant and animal cells where respiration takes place

Question 30

Respiration

Answer 30

A series of chemical reactions that release energy from glucose, takes place in the mitochondria

Question 31

Hydrated iron oxide

Answer 31

F2 O3 H2O

Question 32

Stomata

Answer 32

Microscopic holes in the leaves of plants, where gases like oxygen, carbon dioxide or water vapour can enter and exit the plant

Question 33

Photosynthesis

Answer 33

Endothermic reaction that takes place in green plants, uses energy for sunlight to combine water and carbon dioxide, to produce glucose and oxygen

Question 34

Properties of metals (STEM DLD)

Answer 34

- solid at room temperature - thermal conductors - electrical conductors - malleable - ductile - lustrous - dense

Question 35

What is nanotechnology

Answer 35

The design, production and application of structures, by controlling shape and size at the nanometer scale

Question 36

Difference between strong and weak acids

Answer 36

Strong: when added to water most of its molecules release hydrogen ions into the solution Weak: when added to water, only a few of its molecules release hydrogen ions

Question 37

Properties of acids

Answer 37

- corrosive - sour taste - blue litmus paper red - Conduct electricity - are neutralised by bases

Question 38

Properties of bases

Answer 38

- Caustic - soapy, slimed feel - turns red litmus paper blue - have a bitter taste - conduct electricity

Question 39

Difference between strong and weak bases

Answer 39

Strong: produce lots of hydroxide irons Weak: only produce a few hydroxide ions

Question 40

Acid plus metal

Answer 40

Acid + metal --> salt + hydrogen gas

Question 41

Neutralisation

Answer 41

Acid + base --> salt + water

Question 42

Acid plus carbonate

Answer 42

Acid + carbonate --> salt + water + carbon dioxide

Question 43

Properties of non-metals

Answer 43

- poor conductors of heat and electricity - brittle - relatively low melting and boiling points - dull

Question 44

Metalloid

Answer 44

An element that usually displays the properties of a non-metal but conducts electricity like a metal

Question 45

Malleable

Answer 45

Able to be hammered into new shapes

Question 46

Acid pH

Answer 46

Bellow 7

Question 47

Base pH

Answer 47

Above 7

Question 48

Law of conservation of mass

Answer 48

During a chemical reaction, atoms cannot be created or destroyed

Question 49

Corrosion

Answer 49

The break down of metals due to their reactions with other chemicals

Question 50

Anodising

Answer 50

A way of protecting aluminium from corrosion

Question 51

Photosynthesis equation

Answer 51

Light Carbon dioxide + water -----------> glucose + oxygen Chlorophyll

Question 52

Aerobic respiration equation

Answer 52

Glucose + oxygen ---> carbon dioxide + water + energy

Question 53

Carbon dating

Answer 53

A method of judging the age of fossils by analysing the amount of carbon - 14 in them