c1 particles

Question 1

describe the particles in a solid

Answer 1

very close together
regular, ordered arrangement
vibrate in a fixed position

Question 2

describe the particles in a liquid

Answer 2

close together
random arrangement
flow around eachother

Question 3

describe the particles in a gas

Answer 3

far apart
random arrangement
fast random movements in straight lines in all directions

Question 4

give two properties of a solid

Answer 4

fixed shape and cannot flow
cannot be compressed or squashed

Question 5

give two properties of a liquid

Answer 5

flow and take the shape of their container
cannot be compressed or squashed

Question 6

give two properties of a gas

Answer 6

flow and completely fill their container
can be compressed or squashed

Question 7

what is solid -> liquid

Answer 7

melting

Question 8

what is liquid -> gas

Answer 8

evaporation

Question 9

what is gas -> liquid

Answer 9

condensation

Question 10

what is liquid -> solid

Answer 10

freezing (solidifying)

Question 11

what is solid -> gas

Answer 11

sublimation

Question 12

define chemical change

Answer 12

when atoms are rearranged to form new bonds to make new bonds forming new chemicals

Question 13

define physical change

Answer 13

when a substance changes without becoming a new chemical

Question 14

is a physical or chemical change reversible?

Answer 14

a physical change is usually reversible
a chemical change is usually hard or impossible to reverse

Question 15

what are examples of chemical change

Answer 15

baking
energy change
respiration
photosynthesis
combustion

Question 16

what are examples of physical change

Answer 16

state change
breaking things
changes in shape or size
dissolving

Question 17

what are five limitations to the particle model

Answer 17

1) forces between particles are missing
2) particles can be different sizes, not always the same sized sphere
3) space between the particles is not always shown or accurate
4) particles are 3D not 2D
5) movement of particles can be hard to show on paper

Question 18

what is standard form and how is it written

Answer 18

it is a way of representing either a very large or small number more easily

A x10**n (A can be from 1-10)

Question 19

define an atom

Answer 19

the smallest particle of an element, which still has chemical properties, a positively charged nucleus surrounded by negatively charged electrons, with the nuclear radius much smaller than that of the atom and with most of the mass in the nucleus

Question 20

what is the relative charge of protons neutrons and electrons

Answer 20

p = +
n= no charge
e= -

Question 21

what is the relative mass of protons neutrons and electrons

Answer 21

p = 1
n = 1
e = 0.0005

Question 22

which number is the atomic number

Answer 22

the smaller one

Question 23

what does the atomic number show

Answer 23

the no. of protons

Question 24

what is the no. of electrons equal to

Answer 24

no. of electrons = no. of protons

Question 25

what determines the element of an atom

Answer 25

the number of protons

Question 26

what does the mass number show

Answer 26

no. of protons + no. of neutrons

Question 27

how do you calculate the no. of neutrons

Answer 27

mass number - atomic number

Question 28

who and what are all the atom models

Answer 28

billard ball model - john dalton plum pudding model - jj thompson planetary model - ernest rutherford bohr model - niels bohr electron cloud model - erwin schrödinger

Question 29

define isotopes

Answer 29

atoms of the same element with different numbers of neutrons

Question 30

define an ion

Answer 30

a charged particle which is formed when an atom loses or gains electrons

Question 31

when does a positive ion form (cation)

Answer 31

if electrons are lost

Question 32

when does a negative ion form (anion)

Answer 32

if electrons are gained

Question 33

define chemical formulae

Answer 33

shows the relative number of atoms of each element in a compound

Question 34

define relative atomic mass

Answer 34

the mean mass of an atom of an element compared to 1/12 the mass of a carbon 12 atom

Question 35

define relative formula mass

Answer 35

the mean mass of a unit of substance compared to 1/12 the mass of a carbon 12 atom

Question 36

what is the calculation for relative formula mass

Answer 36

relative atomic mass x no. of atoms

Question 37

define empirical formulae

Answer 37

the simplest whole number ratio of atoms of each element in a compound