Chemistry Term 3

Question 1

Chemical Reaction

Answer 1

A substance formed while others disappear

Question 2

Endothermic reaction

Answer 2

A chemical reaction that absorbs engery

Question 3

Exothermic reactions

Answer 3

A chemical reaction releases energy

Question 4

Combustion

Answer 4

A reaction with oxygen that releases energy

Eg. Heat or light

Question 5

Corrosion

Answer 5

Chemical reactions that form other compounds from metals

Question 6

Periodic table

Answer 6

Elements in a structure that shows the different types and properties

Question 7

Atomic Structure

Answer 7

each element is made up of particles called atoms and atoms are made up of protons, neutrons and electrons

Question 8

Valency

Answer 8

Bonding power of an element, measured by the hydrogen atoms

Eg. Carbon has a valency of 4

Question 9

Octet Rule

Answer 9

The most stable arrangement of electrons, atoms gain or lose electrons to get a full outer valency shell

Question 10

Ions

Answer 10

Charged atoms which have electrons that move from one atom to another

Question 11

Cation

Answer 11

A positive ion, occurs when an electron leaves the atom

Question 12

Anion

Answer 12

A negative ion, occurs when the atom gains an electron

Question 13

What does SVSDF stand for

Answer 13

S-symbol
V-valency
S-swap
D-divide 
F-formula

Question 14

Chemical and word equation of:

Metal+acid->salt+hydrogen

Answer 14

• Hydrochloric acid+sodium->sodium chloride +hydrogen

- 2HCl+2Na->2NaCl+H2

Question 15

Acid

Answer 15

A substance that releases H+ ions when they dissolve in water

Question 16

Bases

Answer 16

A substance that reacts with acids

Question 17

Alkali

Answer 17

A base that is soluble in water

-all alkalis are bases but not all bases are alkalis

Question 18

Strong acids

Answer 18

Dissociate fully into solutions, all H+ released into the mixture

Question 19

Weak acids

Answer 19

Don’t fully dissociate, some H+ stay attached to the acid molecule

Question 20

pH scale

Answer 20

• Measure of the number H+ ions in a solution, with a lower pH meaning more H+
• Strong acids have a lower pH value and are better conductors of electricity

Question 21

Sulphuric acid

Answer 21

H2SO4

Question 22

Hydrochloric acid

Answer 22

HCl

Question 23

Phosphoric acid

Answer 23

H3PO4

Question 24

Photosynthesis

Answer 24

Endothermic reaction that takes place in the green plants;uses energy from sunlight to combine water and carbon dioxide and produce glucose and oxygen gas

Question 25

Respiration

Answer 25

A sense of chemical reaction is that releases energy from glucose; it takes place in the mitochondria inside cells

Question 26

Chemical equation for photosynthesis:

Answer 26

Carbon dioxide+water —> glucose+oxygen | 6CO2+6H2O —> C6H12+6O2

Question 27

Chemical equation for respiration:

Answer 27

Glucose+oxygen —> carbon dioxide+water | C6H12O6+6H2O —> 6CO+6H2O

Question 28

Aerobic respiration

Answer 28

Respiration that uses oxygen

Question 29

Anaerobic respiration

Answer 29

Respiration that doesn’t require oxygen

Question 30

Radiation

Answer 30

When energy is emitted by substances, particles or waves emitted by radioactive substances

Question 31

Geiger counter

Answer 31

Device used to measure radiation

Question 32

Alpha particles

Answer 32

- Particles made up of two protons and two neutrons | - take 4 on top and take 2 on bottom

Question 33

Beta particles

Answer 33

- Negativity charged particles that can be ejected from the nucleus - top stays the same and bottom take one

Question 34

Gamma radiation

Answer 34

- Ionising radiation made of gamma rays which releases energy in the form of electromagnetic radiation - doesnt change

Question 35

Enthalpy

Answer 35

Activation energy, the activated complex and the effect of a catalyst

Question 36

Entropy

Answer 36

The tendency towards disorder

Question 37

Catalyst

Answer 37

Substance that speeds up a chemical reaction by lowering the Ea