chem

Question 1

what is an element

Answer 1

a substance that can not be broken down chemically

Question 2

whats a compound

Answer 2

at least 2 elements combined together in fixed proportions

Question 3

how do you separate compounds into elements

Answer 3

by creating a chemical reaction eg to get the element copper back the oxygen needs to be chemically removed with hydrogen

Question 4

what is a giant covalent molecules

Answer 4

many atoms joined together by covalent bonds

Question 5

describe a giant covalent molecule

Answer 5

• they are always solid at room temperature

- they have very high melting and boiling points

Question 6

what element is diamond formed from

Answer 6

carbon

Question 7

what is graphene

Answer 7

a single layer of graphite. its one atom thick.

Question 8

explain graphene

Answer 8

• good conductor of electricity

- extremely strong

Question 9

what is fullerene

Answer 9

it is a molecule of carbon atoms with hollow shapes

Question 10

explain Fullerene

Answer 10

• high tensile
• good conducts of heat/electricity
• used to reinforce molecules

Question 11

what are the 3 states of matter

Answer 11

solid, liquid and gas

Question 12

what are the 3 types of strong chemical bonds

Answer 12

metallic , covalent , ionic

Question 13

what is ionic bond?

Answer 13

compounds formed from metals combined with non metals

Question 14

what is covalent bond

Answer 14

compounds of non metals and in most non metallic elements

Question 15

what is metallic bonds

Answer 15

is a compound of metallic elements and alloys

Question 16

how do atoms joined together

Answer 16

they can join together by transferring electrons or by sharing electrons

Question 17

what happens when metals and non metals transfer electrons

Answer 17

the atoms become charged

Question 18

what are charged atoms called

Answer 18

ions -the metal ions are positively charged and the non metal ions are negatively charged

Question 19

whats a mixture

Answer 19

a mix of substances

Question 20

what are substances made of

Answer 20

mixtures, compounds or elements

Question 21

explain separation of mixtures

Answer 21

mixtures can easily be separated because the chemicals in them are not joined together.

Question 22

how are mixtures seperated

Answer 22

mixtures can be separated filtration , crystallisation, simple distillation , fractional distillation, chromatography

Question 23

what does filtration do

Answer 23

its separates insoluble substances from soluble substances

Question 24

what does distillation do

Answer 24

it separates liquids that have different boiling points

Question 25

What is a an tom made up of t

Answer 25

It’s made up of a nucleus that is surrounded by electrons. the nucleus carries the positive charge and the electrons which surround the nucleus carry negative charge .