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