C1

Question 1

What is the relative charge of:
a) a proton
b) an electron
c) a neutron

Answer 1

a) proton= +1

b) electron= -1

c) neutron= 0

Question 2

What are the relative masses of the three sub-atomic particles?

Answer 2

• proton= 1
• neutron= 1
• electron= virtually nothing

Question 3

What is the radius of an atom and the nucleus of an atom?

Answer 3

• atom= 1 x 10^-10
• nucleus= 1 x 10^-14

Question 4

What is an element?

Answer 4

An element is substance made up of only one type of atom

Question 5

What is an ion?

Answer 5

an ion is an atom or element that has lost or gained electrons, therefore giving it a charge

Question 6

True or False? Elements only contain atoms with the same number of protons.

Answer 6

True

Question 7

What does the relative mass number of an element tell us?

Answer 7

the total number of protons and neutrons

Question 8

What does the relative atomic number of an element tell us?

Answer 8

the number of protons

Question 9

Define an isotope

Answer 9

An isotope is a form of an element with the same number of protons but a different number of neutrons

Question 10

Define a molecule

Answer 10

A molecule is two or more atoms, held together by chemical bonds

Question 11

What is the difference between mixtures and compounds?

Answer 11

A compound is two or more different elements that are chemically combined in fixed proportions bonds whilst a mixture is two or more elements that are not chemically joined

Question 12

Before the discovery of the electron, what were atoms thought to be?

Answer 12

Tiny spheres that could not be divided

Question 13

What did the discovery of the electron lead to and what did this model suggest?

Answer 13

The plum pudding model:
the atom is a ball of positive charge with
negative electrons embedded in it

Question 14

Which scientist did the alpha particle scattering experiment and what conclusions could be made from the experiment?

Answer 14

Ernest Rutherford

1. the mass of an atom in concentrated in the centre
2. the atom is mostly empty space
3. the nucleus was charged

Question 15

What replaced the plum pudding model and how did Neil Bohr adapt the model?

Answer 15

The nuclear model

he suggested that electrons orbit the nucleus at specific distances; his theoretical calculations agreed with experimental observations

Question 16

Who provided evidence of the neutron within the nucleus?

Answer 16

James Chadwick

Question 17

What are the 5 methods that can be used to separate mixtures?

Answer 17

1. Filtration
2. Crystallisation
3. Simple Distillation
4. Chromatography
5. Fractional Distillation

Question 18

Describe when simple distillation is used and explain

Answer 18

Used to separate a liquid from a solution (with different boiling points) e.g. separating pure water from sea water

• Equipment-conical flask, thermometer, condenser, beaker, Bunsen burner

• The mixture is heated up so the liquid we want evaporates as it rises up the pressure will force it down the condenser and the vapor will cool and condense into a liquid that would flow into the beaker

Question 19

Describe when fractional distillation is used and explain

Answer 19

used for separating mixtures of liquids with different boiling points

• equipment-fractionating column, conical flask condenser

• The mixture would be heated to the boiling point of the substance which has a lower boiling point, causing it to evaporate and rise up the fractionating column and pass into the condenser and cool into liquid that will flow into the beaker
• Same thing done again to heat the remaining mixture the next boiling point

Question 20

Why can evaporation always be used to separate soluble solids from solutions?

Answer 20

some solids decompose when heated (thermal decomposition)

Question 21

Describe and explain crystallisation

Answer 21

separates solutions into their different parts: dissolved solids(solutes) and liquids(solvents) & separates a soluble solid from a solution

• equipment: crucible(evaporation dish), tripod, Bunsen burner or water bath, heat proof mat, filter paper, funnel

1. Place the solution into a crucible and heat it gently(a water bath would be appropriate)
2. Once some of the solvent has evaporated and you can see crystals forming stop heating the solution
3. Leave the solution to cool. As the solution cools more crystals will start to form (because solids are less soluble at colder temperatures)
4. filter out the solution using filter paper and a funnel
5. dry the crystals e.g. by leaving them somewhere warm.

Question 22

Describe and explain filtration

Answer 22

used to separate insoluble solids and
liquids

• equipment- funnel, filter paper, beaker
- the mixture is poured through the filter paper

• the insoluble solid is trapped by the filter paper whilst the liquid runs through and is collected below

Question 23

Describe and explain chromatography

Answer 23

used to separate solutions with a number of different solutes in the solvent

• equipment: filter paper, beaker, solvent(e.g.) water, pencil

1. draw a line on the filter paper in pencil and place dots of ink along the line
2. fill the beaker with the solvent but make sure it is below the pencil line
3. as the solvent moves up the paper it carries the solutes with it (different solutes move at different speeds so they separate.)

Question 24

How are the elements of the periodic table arranged?

Answer 24

The elements are arranged by atomic number

Question 25

What are the rows called?

Answer 25

Periods

Question 26

What are the columns called?

Answer 26

Groups

Question 27

What does the period and group of an element tell you?

Answer 27

group number= number of electrons on the outer(most) shell period=number of shells

Question 28

How was the periodic table arranged before?

Answer 28

by atomic weight

Question 29

How did Dimitri Mendeleev fix the periodic table

Answer 29

- left gaps for elements he believed were yet to be discovered - changed the order based atomic weights to atomic number

Question 30

Where are metals located on the periodic table?

Answer 30

To the left (of the ‘stairs’)

Question 31

Where are the non-metals located?

Answer 31

to the right of the ‘stairs’

Question 32

What is the difference between metals and non-metals ?

Answer 32

non-metals - form negative ions (anions), dull, poor conductors, brittle metals- form positive ions (cations), shiny, malleable, good conductors of electricity + heat , ductile

Question 33

What is group 0 known as and what are properties/trends of group 0?

Answer 33

Noble gases - they are inert as they have a full outer shell (typically 8, but 2 for helium) - the boiling/melting points increase as you go down the group

Question 34

What are group 1 metals known as and what are properties/ trends of group 1 metals?

Answer 34

Alkali metals - soft - low density - low boiling point - highly reactive- easy to lose the single outer electron - boiling/ melting points decrease as you go down the group - reactivity increases as you go down the group because the distance from the nucleus increases and this means there are weaker forces of attraction between the outer electron and nucleus

Question 35

How do group 1 metals (alkali metals) react with: a)water b)oxygen c)chlorine

Answer 35

Water ~ react vigorously and form metal hydroxide + hydrogen Oxygen ~ vigorous, react to produce metal oxides: sodium oxide, sodium peroxide, potassium peroxide, potassium superoxide etc... Chlorine ~ react vigorously, ionic compounds with chlorine

Question 36

What are group 7 metals known as and what are the properties/trends of group 7 metals?

Answer 36

Halogens - the reactivity decreases as you go down the group- weaker attraction means it’s harder to gain and electron - as you go down the group the melting and boiling point increases - more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt

Question 37

True of False: group 7 elements are not found in pairs

Answer 37

False: group 7 elements are diatomic

Question 38

compare: Transition metals vs Group 1 metals

Answer 38

- transition metals are harder, greater strength - transition metals have higher boiling points and densities - transition metals have ions with different charges whilst group 1 metals only have one - transition metals can form coloured compounds - transition metals can be used as catalysts(e.g. Iron in the haber process) - reaction with oxygen: very slow or not at all(at room temp) vs. group 1 elements which react quickly with oxygen - reaction with water: very slow with cold water or not at all - some transition metals react to with halogens such as iron