Year 10 Exams

Question 1

What is a cation

Answer 1

A positively charged ion

Question 2

What is an anion

Answer 2

A negatively charged ion

Question 3

What is an ion?

Answer 3

An atom or group of atoms with a positive or negative charge

Question 4

What is atomic number

Answer 4

Number of protons/electrons

Question 5

What is mass number

Answer 5

Number of protons + neutrons

Question 6

what is an isotope

Answer 6

different forms of the same element - same number of protons and electrons but a different number of neutrons

Question 7

what is relative atomic mass

Answer 7

average mass of one atom of the element compared to 1/12 of the mass of one atom of carbon 12

Question 8

how to work out relative atomic. mass

Answer 8

multiply the isotope number after the element by the abundance
divide by the sum of the abundance

Question 9

how to tell what group element is in by electronic configuration

Answer 9

number of electrons on outer shell

e.g. 2.8.3 is in group 3

Question 10

how to tell what period an element is in from electronic configuration

Answer 10

how many shells (digits of electronic configuration)

e.g. 2.7 is in period 2

Question 11

what is a chemical change

Answer 11

when bonds between atoms break and the atoms change places and a new substance is formed

hard to reverse

Question 12

difference between a pure substance and a mixture

Answer 12

pure - consists of only one element or compound

mixture - two or more different substances, not joined together

Question 13

pure orange juice isn’t pure because

Answer 13

it has different substances mixed together so it’s not pure in a chemical sense

Question 14

when line goes flat on a heating graph what happens

Answer 14

its changing state - energy we put in is breaking the forces of attraction between particles, allowing it to change state

during the change of state we are increasing the internal energy store but NOT changing the temperature

Question 15

how do you know if a substance is pure

Answer 15

they have a specific melting point and boiling point

Question 16

how do you know if a substance is a mixture

Answer 16

it will melt or boil over a range of temperatures

Question 17

how can waste and ground water become potable (drinkable)

Answer 17

pour bad water into a distillation flask
heat it with a bunsen burner
put a thermometer in it
use a rubber tubing to connect condenser to a cold tap
water vapour passes into condenser where it cools and condenses
flows into a beaker to collect the pure water

Question 18

how to separate a mixture of liquids

Answer 18

put mixture in a flask
put thermometer
attach a fractionating column and condenser above the flask
heat the flask
the liquids will have diff boiling points so they will evaporate at diff temperatures
they condense at the top bc it’s cooler
keep raising temp until u get all liquids

Question 19

what is solidification

Answer 19

soluble salts precipitate as lumps and then settle at the bottom

it removes ions and salts from the water

Question 20

what is filtration

Answer 20

water goes through the sand and gravel to get rid of even smaller bits

it removes smaller solids

Question 21

what is chlorination

Answer 21

adding chlorine to the water to get rid of bacteria

removes bacteria

Question 22

acronym for the stages of filtration

Answer 22

sorry - solidification
forgot - filtration
can’t - chlorination

Question 23

covalent bond RULES

Answer 23

write down how many electrons in outer shell
write down how many electrons each atoms need to make a full outer shell
this is how many bonds will form
draw the structural diagram of the molecule
draw dot and cross diagram (only use outer shells)
put the atom with the highest number of bonds in the middle
draw dots and crosses for electrons

Question 24

diamond vs graphite

Answer 24

diamond: poor conductor of electricity graphite: good conductor of electricity

diamond and graphite: high melting

Question 25

why is graphite used for pencils

Answer 25

it’s soft so the carbon atoms form layers which are able to slide over each other

layers of hexagonal sheets - easy to break

Question 26

how many covalent bonds does diamond have

Answer 26

four

Question 27

why is graphite a good conductor of electricity

Answer 27

it has 3 covalent bonds meaning it has a spare, delocalised electron to carry around charge

Question 28

what do ionic compounds have

Answer 28

regular lattice arrangement
strong electrostatic forces of attraction between oppositely charged ions

Question 29

ionic compound properties

Answer 29

high melting boiling point

can’t conduct electricity due to ions held in place (except graphite)

when they melt, electrons are free to flow and carry charge

some dissolve in water so the ions separate and are free to move around

Question 30

limitations of structural models

Answer 30

2D representations don’t show shape of substances or size of atoms

dot and cross diagrams don’t show anything about size or how ions or atoms are arranged

3D models only show outer layer of the substance but are good at showing arrangement of ions

Question 31

what’s a covalent bond

Answer 31

strong bond that forms when a pair of electrons are shared between two atoms

Question 32

simple molecular substance properties

Answer 32

weak forces of attraction between molecules

weak intermolecular forces

gases or liquids at room temp

don’t conduct electricity - has no charge or no free electrons