science chemistry

Question 1

what is an atom

Answer 1

they are basic building blocks of matter and contain a central nucleas with protons,neutrons and electrons surrounding it

Question 2

how is a positive ion formed

Answer 2

it loses electrons

Question 3

what is an ionic bonding

Answer 3

a strong force between oppositely charged metals

Question 4

what is metallic bonding

Answer 4

its forces of attraction between oppositely charged to hold the metals together.

Question 5

when can ionic compounds conduct electricity

Answer 5

when ions can move e.g. in liquids when compounds are dissolved

Question 6

endothermic-

Answer 6

takes in energy from surroundings e.g. melting

Question 7

exothermic-

Answer 7

gives out energy to surroundings e.g freezing

Question 8

reaction profile-

Answer 8

shows chnages of reactants and products during reaction

Question 9

rate of reaction-

Answer 9

how fast a reaction occurs

Question 10

example of slow rate of reaction-

Answer 10

rusting

Question 11

how do you measure the rate of reaction

Answer 11

you measure how quickly reactants are used up or how quickly product is made

Question 11

two things needed for two particles to react

Answer 11

must collide hard enough or with enough energy

Question 12

reaction occur faster when

Answer 12

more reactant particles collide with each other

Question 13

a way to increase the number of colliding particles

Answer 13

increase surface area of a reactant

Question 14

why do reactions get slower as they progress

Answer 14

there are fewer and fewer reactant particles

Question 15

what is salt

Answer 15

is an ionic compound produced by neutralisation reaction

Question 16

what is neuatralisation

Answer 16

an acid that reacts with an alkali or a base to form a salt or water

Question 17

state symbols

Answer 17

liquid-(L) as-gas-(g) solid-(s) and aqueus(aq)

Question 18

what is a reversible reaction

Answer 18

its a reaction that can go forwards and backwards

Question 19

what is dynamic equilibrium

Answer 19

when forwards and reverse procceses occur at same time,resulting in no overall observable change

Question 20

3 main types of bonds are

Answer 20

metallic
ionic
covalent

Question 21

why are metals strong

Answer 21

force of attraction between ions and electrons keeps metal together

Question 22

what is explosion

Answer 22

sudden increase in volume of gas and huge transfer of energy to surroundings

Question 23

wha is physical changes

Answer 23

changes where no new substances are made

Question 24

what r chemical changes

Answer 24

changes where 1 or more new substances r made

Question 25

term flammable-

Answer 25

a substance catches fire easily

Question 26

reactants

Answer 26

the starting substances used to make products

Question 27

product

Answer 27

a new substance formed by reactants

Question 28

gas pressure

Answer 28

the force gas particles exert by hitting walls of the container

Question 29

how to increase gas pressure

Answer 29

-increase temperautre
-increase the number of articles
-decrease size of container

Question 30

metals n water-

Answer 30

hydroxide and hydrogen

Question 31

metals n oxygen-

Answer 31

metal oxides

Question 32

oxidation?-

Answer 32

a reaction where a substance reacts,combines and gains oxygen

Question 33

how to protect rust

Answer 33

use a barrir or paint/oil/plastic to prevent air/water

Question 34

how id rust formed

Answer 34

formed by the corrision of iron and rust

Question 35

how is gunpowder made

Answer 35

mix pottasium nitrate and powdered charcoal

Question 36

an exothermeric reaction e.g.

Answer 36

combustion

Question 37

an endothermic reaction e..g

Answer 37

thermal decomposition

Question 38

what is displacement reaction

Answer 38

a reaction where a more reactive metal displaces a less reactive metal

Question 39

what is native state

Answer 39

when a metal is found in the earth as an elemant

Question 40

what is ore-

Answer 40

rock that contains enough mineral to be worht mining

Question 41

a way to extract iron-

Answer 41

heating with carbon

Question 42

whta is electrolysis

Answer 42

a way to extract reactive metal using electricity

Question 43

an example reaction which can electrolysis

Answer 43

aluminium pottasium