workbook 1

Question 1

describe the mass of the subatomic particles

Answer 1

protons and neutrons are equivalent to 1.

electrons are so light they aren’t counted as anything.

Question 2

describe the nucleus

Answer 2

small and dense and contains 99% of the mass.

Question 3

what are the charges of subatomic particles

Answer 3

proton: +
electron: -
neutron: neutral (none)

Question 4

what is a nuclide

Answer 4

representation of an element

Question 5

what does the top number (A) on a nuclide represent

Answer 5

the atomic mass

Question 6

how do you calculate the atomic mass

Answer 6

protons+neutrons

Question 7

what does the bottom number (Z) represent in a nuclide

Answer 7

the number of protons

Question 8

what is an isotope

Answer 8

an element with the same number of protons to keep its identity but a different number of neutrons.

Question 9

what is the bohr model

Answer 9

an early model of an atom where the electrons orbit the nucleus is specific energy levels or shells.

Question 10

why do ionic compounds form

Answer 10

an atom is stable if all orbital shells are full. with a single atom this is only possible with the noble gases. to fill shells, atoms combine to form stable outer shells.

Question 11

what is an example of an ionic compound

Answer 11

sodium and chlorine

they join so that sodium can give chlorine its valence electron and therefore they have a full outer shell and are stable.

Question 12

why do groups have the same amount of valence electrons

Answer 12

because they have similar chemical properties

Question 13

what is the electron configuration

Answer 13

2, 8, 8, 2

• then begins filling other shells and becomes more complicated.

Question 14

what are periods (periodic table)

Answer 14

the rows going across the table

*period= period of time… timeline is horizontal

Question 15

what are groups (periodic table)

Answer 15

the columns going down the table

Question 16

what is group 1 in the periodic table

Answer 16

alkali metal

Question 17

what is group 2 in the periodic table

Answer 17

alkali earth metal

Question 18

what is group 17 in the periodic table

Answer 18

halogens

Question 19

what is group 18 in the periodic table

Answer 19

nobel gases

Question 20

what are the 6 properties of metals

Answer 20

1. good conductors of electricity
2. hard
3. malleable and ductile
4. high density
5. form positive ions
6. high melting and boiling points

Question 21

what are 5 properties of nonmetals

Answer 21

1. low conductors
2. brittle or soft
3. form negative ions
4. low density
5. low melting and boiling points

Question 22

what are three trends in the periodic table

Answer 22

1. ionisation energy
2. atomic radius
3. electronegativity

Question 23

what is ionisation energy

Answer 23

the energy required to remove an electron from the outermost bracket/shell

Question 24

what is the trend of ionisation energy on a periodic table

Answer 24

increases across a period
decreases down a group

Question 25

why does ionisation energy change across a period

Answer 25

due to an increasing nuclear charge which pulls valence electrons closer to the nucleus, making them harder to remove

Question 26

why does ionisation energy change down a group

Answer 26

the valence electrons are located further away from the nucleus resulting in a decrease in electrostatic attraction the other electrons are shielding outer electrons from the nuclear charge

Question 27

how do you read ionisation energies in graphs

Answer 27

in a table/graph there will be a large gap in the energy taken to remove a valence electron. The jump is a result of the outermost shell being empty and moving closer to the nucleus. energies before a big jump equals the number of valence electrons.

Question 28

what is the trend of the atomic radius on a periodic table

Answer 28

decreases across a period increases down a group

Question 29

why does the atomic radius change across a period

Answer 29

the increasing nuclear charge pulls the valence shells/electrons in closer so the radius decreases

Question 30

why does the atomic radius change down a group

Answer 30

there is a general increase due to the increase in subatomic particles

Question 31

what is electronegativity

Answer 31

a measure of the atoms ability to attract electrons

Question 32

what is the trend of the electromagnetic negativity on a periodic table

Answer 32

it increases across a period it decreases down a group

Question 33

how does electromagnetic negativity change across a period

Answer 33

the increasing number of protons attracts electrons - increases

Question 34

how does electromagnetic negativity change down a group

Answer 34

there is an increase in electron orbits that shield the inner electrons and nucleus

Question 35

describe the emission spectrum

Answer 35

is formed by heating a gas. The electrons in the gas become excited and move to higher energy levels, as they fall back to ground state they emit photons (light energy). The light that is emitted from the gas passes through a diffraction grating. This produces a spectrum with a black background with coloured lines.

Question 36

describe the absorption spectrum

Answer 36

is formed by a light passing through a cool gas. The photons from the light source bump into electrons in the cool gas. If the frequency of the photon matches the energy needed by the electron, it will become excited and jump up to a higher energy level. As it jumps up a shell, it absorbs the photon. The light produces a continuous spectrum, the cool gas Infront of it acts as a filter and the absorbed photons leave gaps in the continuous spectrum making it an absorption spectrum.

Question 37

how is each elements spectrum unique

Answer 37

each element has a unique spectrum that can be identified. They are all unique because each element has a different structural composition which effects the differences in energies between each shell.

Question 38

what is a continuous spectrum

Answer 38

contains all wavelengths of life so it appears as a rainbow. they are emitted from hot, dense objects like stars.

Question 39

what is a flame test

Answer 39

a flame test involves heating a sample of the substance over a flame, which causes the electrons to become excited and release photons

Question 40

what can the flame test be used for

Answer 40

can be used to detect the presence of metal ions in a substance through the characteristic emissions of each element.

Question 41

how do you calculate relative atomic mass

Answer 41

Ar= %a x Ar(a)+ %b x Ar(b)100

Question 42

what is the formula for percentage composition

Answer 42

%comp= mass of element/mass of sample x 100