Chapter 2

Question 1

What are reactants?

Answer 1

Substances before a chemical reaction

Question 2

What are products?

Answer 2

Substances after chemical reactions

Question 3

Steps to writing word equations

Answer 3

Identify the reactants and products, write a word equation

Question 4

What are exothermic reactions?

Answer 4

Ones that release energy in the form of heat and light

Question 5

What are endothermic reactions

Answer 5

Reactions that absorb energy

Question 6

When does a combustion reaction occur

Answer 6

When something reacts with oxygen gas and burning or exploding as it reacts

Question 7

What are highly combustible fuels called

Answer 7

Hydrocarbons

Question 8

What is a complete combustion?

Answer 8

When sufficient oxygen is present

Question 9

What is an incomplete combustion?

Answer 9

When the oxygen supply is limited

Question 10

What are metal oxides?

Answer 10

When metals are burnt with oxygen

Question 11

What is corrosion?

Answer 11

When a metal reacts to oxygen or water to form another substance

Question 12

What do nuclear reactions do to the atom?

Answer 12

Converts a specific atom into a different one

Question 13

What may happen to the nucleus during a nuclear reacton?

Answer 13

Emits high energy electromagnetic radiation

Question 14

What is photosynthesis?

Answer 14

The reaction that allows plants to produce food

Question 15

Where does photosynthesis take place?

Answer 15

The leaf

Question 16

How does photosynthesis happen?

Answer 16

Carbon dioxide moves by diffusion into the stomata, water is carried from the roots to leaves and sunlight is captured by chloroplast

Question 17

What is respiration?

Answer 17

How plants and animals gain energy

Question 18

Where does the glucose and oxygen react?

Answer 18

Mitochondria

Question 19

What is nuclear decay?

Answer 19

When the nucleus emits high energy electromagnetic radiation

Question 20

What are isotopes?

Answer 20

Atoms with the same number of protons and electrons, but not the same neutrons

Question 21

What do most isotopes contain?

Answer 21

A stable nuclei (not undergo nuclear decay)

Question 22

What happens to the isotopes that do not have a stable nuclei?

Answer 22

Form other elements. Called radioisotopes

Question 23

What are the 3 types of nuclear decay?

Answer 23

Alpha, Beta, Gamma

Question 24

What is alpha decay?

Answer 24

When a heavy nucleus releases an alpha particle, i.e. 2 protons and 2 neutrons

Question 25

What is beta decay?

Answer 25

When the nucleus releases a beta particle to create an extra proton

Question 26

What is gamma decay?

Answer 26

When the nucleus rearranges itself and releases gamma rays

Question 27

How does carbon dating work?

Answer 27

Measuring C-14

Question 28

What is used to determine the age of fossils?

Answer 28

Half-life of carbon-14

Question 29

What is ionising radiation?

Answer 29

When nuclear radiation removes electrons fron atoms or molecules, causing cells to die or mutate

Question 30

Hydrocarbon formula

Answer 30

hydrocarbon + oxygen → carbon dioxide + water

Question 31

Respiration formula

Answer 31

glucose + oxygen gas → carbon dioxide + water vapour

Question 32

What are oxides?

Answer 32

Things combined with oxygen

Question 33

What happens when acid reacts with metal

Answer 33

Forms salt and hydrogen

Question 34

What happens when acid reacts with bases?

Answer 34

Makes salt and water

Question 35

What happens when acids react with carbonates?

Answer 35

Forms salt + water + carbon dioxide

Question 36

What is heartburn?

Answer 36

Caused by hydrochloric acid from the stomach rising into the oesophagus and burning it.

Question 37

Hydrochloric acid formula

Answer 37

HCI

Question 38

Sulfuric acid formula

Answer 38

H2SO4

Question 39

Nitric acid formula

Answer 39

HNO3

Question 40

What is pepsin

Answer 40

An enzyme that helps digest proteins in the stomach