C1 - Particles

Question 1

what are some properties of solids

Answer 1

they cannot be compressed. they cannot diffuse/flow. they have a fixed shape. they have low kinectic energy

Question 2

what are some properties of liquids

Answer 2

their shape is at the bottom of a container. they can flow. their shape fits to a container. diffusion can happen. they cannot be compressed. their kinectic energy is low to medium

Question 3

what are some properties of gases

Answer 3

they fill containers. they can be compressed. they can flow. they can be diffused. their kinectic energy is high

Question 4

what is an example of a solute

Answer 4

salt

Question 5

what is an example of a solvent

Answer 5

water

Question 6

what is an example of a solution

Answer 6

brine

Question 7

physical changes are changes of….

Answer 7

state.
shape.
being broken into pieces

Question 8

is dissolving a chemical or physical change

Answer 8

dissolving is a physical change

Question 9

are physical changes reversible or irreversible

Answer 9

physical changes tend to be reversible so no new substances are made

Question 10

what are chemical changes

Answer 10

chemical changes are permanent changes where an atom or molecule chemically joins to anoother atom or molecule

Question 11

are chemical changes reversible or irreversible

Answer 11

chemical changes tend to be irreversible

Question 12

what are some limitations of the particle model

Answer 12

particles aren’t really spheres. particles are different sizes to each other. little account is taken of the intermolecular forces between particles. the size of the spaces between particles is not taken into account. electron structure is ignored - particles look solid.

Question 13

what is an element

Answer 13

a substance made of only one type of atom

Question 14

what is a compound

Answer 14

a substance made of at lease 2 types of elements or atoms chemically combined e.g. H20

Question 15

what is a molecule

Answer 15

a substance/particle made of at least 2 atoms chemically combined e.g. H20 and 02

Question 16

when was the first mention of the atom by greek philosophers

Answer 16

430BC

Question 17

what did Thomson suggest after discovering the electron in 1897

Answer 17

homson suggested the atom was like a plum pudding with the raisins in the pudding representing the negative electrons embedded in a sphere of positive charge

Question 18

who were Thomson’s students

Answer 18

Ernest Rutherford, Geiger and Marson

Question 19

what was Thomson’s experiment

Answer 19

particles called alpha were fired through a vacuum at a very thin gold leaf (10 atoms thick). alpha particles were known to be very small and positively charged. more alpha particles went straight through or were deflected very slightly as expected from the plum pudding model. around 1 in 8000 were deflected by more than 90°

Question 20

what conclusion did Thomson make

Answer 20

he atom must have a nucleus which is very dense, small and highly positively charged. the rest of the atom is almost entirely space

Question 21

what did Neils Bohr realise

Answer 21

Neils Bohr realised that quantum physics meant that electrons could only be found in very distinct energy levels around the atoms called shells that trying to pin point where they were within that shell at any time was impossible

Question 22

how small are atoms in mm

Answer 22

1x10^-7 mm

Question 23

what state is carbon dioxide, at room temperature

Answer 23

colourless gas

Question 24

what state are ozone, ammonia, nitrogen and oxygen at room temperature

Answer 24

gas

Question 25

what state are carbon and iodine at room temperature

Answer 25

solid

Question 26

where are the protons and neutrons in an atom

Answer 26

the protons and neutrons are in a dense nucleus

Question 27

where are the electrons in an atom

Answer 27

in shells around the outside

Question 28

what is the relative mass of a proton

Answer 28

1

Question 29

what is the relative charge of a proton

Answer 29

+1

Question 30

what is the relative mass of a neutron

Answer 30

1

Question 31

what is the relative charge of a neutron

Answer 31

0

Question 32

what is the relative mass of an electron

Answer 32

almost 0

Question 33

what is the relative charge of an electron

Answer 33

-1

Question 34

what is the atomic number

Answer 34

the atomic number is the number of protons/electrons

Question 35

how do you calculate the mass number

Answer 35

the mass number = protons + neutrons

Question 36

how do you calculate the neutrons

Answer 36

neutrons = mass number - number of protons

Question 37

what is the relative mass of a neutron

Answer 37

mass number - atomic number

Question 38

what are isotopes

Answer 38

isotopes are atoms of the same element that have the same number of protons/electrons but a different number of neutrons. isotopes have the same atomic number but different mass number

Question 39

why do isotopes of an element have identical chemical properties

Answer 39

isotopes of an element have identical chemical properties as they have the same number of electrons

Question 40

do isotopes of the same element have the same physical properties

Answer 40

no, only if chemical

Question 41

what is an atom

Answer 41

the smallest particles that can exist on its own

Question 42

what is an electron

Answer 42

negatively charged particles that orbits the nucleus of an atom

Question 43

what is a neutron

Answer 43

a neutral particles, with a mass of 1. it is found in the nucleus of an atom

Question 44

what is a nucleus

Answer 44

the dense, positively charged centre of an atom, made up of protons and neutrons

Question 45

what is the molecular formula

Answer 45

the number of protons in the nucleus of an atom, also known as the proton number

Question 46

what happens to particles when they are heated (given heated)

Answer 46

when particles are heated, the energy causes them to move more

Question 47

do particles vibrate in a solid

Answer 47

yes - particles vibrate in a solid

Question 48

at what temperature does water change state from solid to liquid

Answer 48

at 0°C

Question 49

what is the melting point

Answer 49

when water changes state from solid to liquid

Question 50

what happens to water molecules if water is heated

Answer 50

water molecules will move faster

Question 51

at what temperature do the water molecules change from liquid to solid

Answer 51

at 100°C

Question 52

what is the boiling point

Answer 52

when water molecules change state from liquid to solid

Question 53

what does the particle model use, in order to represent particles

Answer 53

the particle model uses circles or spheres to represent particles

Question 54

when is an ion formed

Answer 54

an ion is formed when an element gains or loses electrons

Question 55

what state is it, if the melting point is higher than the given temperature

Answer 55

solid

Question 56

what state is it, if the given temperature is between the melting and boiling points

Answer 56

liquid

Question 57

what state is it, if the given temperature is higher than the boiling point

Answer 57

gas

Question 58

what does the period number tell us

Answer 58

the period number tells us how many electron shells there are

Question 59

what does the group number tell us

Answer 59

the group number tells us how many electrons there are on the outer shell