Topic 1 - Atomic Structure

Question 1

What are the three subatomic particles? (and their charges?)

Answer 1

protons (+1)
neutrons (0)
electrons (-1)

Question 2

What are the relative masses of the subatomic particles?

Answer 2

proton 1
neutron 1
electron 0.0005 or 1/2000

Question 3

What does the atomic number show?

Answer 3

number of protons

this is always the smaller number on the periodic table

Question 4

What are cations?

Answer 4

Positive ions

have fewer electrons than protons

Question 5

What are anions?

Answer 5

Negative ions

have more electrons than protons

Question 6

What are isotopes?

Answer 6

atoms with the same number of protons but different numbers of neutrons
-the number/arrangement of electrons determine chemical properties so they still have the same chemical properties but different physical properties (as they are determined by mass)

Question 7

What is relative atomic mass (RAM)?

Ar

Answer 7

the weighted mean mass of an atom compared to 1/12th of the mass of an atom of carbon-12

Question 8

What is relative isotopic mass (RIM)?

Answer 8

the mass of an atom of an isotope compared to 1/12th the mass of an atom of carbon-12

Question 9

What is relative molecular mass (RMM)?

Mr

Answer 9

the average mass of a molecule or formula unit compared to 1/12th of the mass of an atom of carbon-12

Question 10

RAM =

relative atomic mass

Answer 10

(RIM x %) + (RIM x %)
________________
100

Question 11

What are mass spectrometers?

Answer 11

devices that are used to find out what samples are made up of by measuring the masses of their components
(this gives us the relative atomic masses and their abundances)

Question 12

What is the M+ peak (on a mass spectrum)?

Answer 12

molecular ion peak

• this is the peak furthest to the right
• the value of the M+ peak is the same as its molecular mass

Question 13

What are the axis labels on mass spectra?

Answer 13

y axis - relative abundance (%)

x axis - mass/charge or m/z

Question 14

What is the M+1 peak (on a mass spectra)

Answer 14

a peak with small abundance the furthest to the right with a mass one more than its molecular mass
this is caused by an isotope

Question 15

What are the different types of subshells?

Answer 15

s
p
d

Question 16

What is the shape of a s-orbital?

Answer 16

sphere

Question 17

What is the shape of a p-orbital?

Answer 17

two balloons tied together at the knot

Question 18

How many orbitals are in each subshell?

Answer 18

1 orbital in s subshell (2e-)
3 orbitals in p subshell (6e-)
5 orbitals in d subshell (10e-)

Question 19

What is an orbital?

Answer 19

a region of space within an atom that up to 2 electrons move within (spin in opposite directions)

Question 20

Where are the shells with greatest energy positioned in comparison to the nucleus?

Answer 20

the shells furthest from the nucleus have most energy

Question 21

What is electrons in boxes used to show?

Answer 21

electron configuration

the electrons in their orbitals

Question 22

What is spin-pairing?

Answer 22

the idea that electrons in each orbital spin in opposite directions to eachother

Question 23

What is subshell notation?

Answer 23

a way of showing electron configuration by showing how many electrons are in each subshell of each energy level

Question 24

What are the three different blocks of the periodic table?

Answer 24

s-block (on the left)
p-block (on the right)
d-block (in the middle)

Question 25

What does it mean when an electron is “excited”?

Answer 25

electrons are excited when they gain energy so jump to a higher energy level

Question 26

What does an emission spectrum show?

Answer 26

the frequencies of light emitted when electrons drop down from a higher energy level to a lower one

Question 27

What does the mass number show?

Answer 27

the total number of protons and neutrons in an atom

Question 28

What is an ionisation energy?

Answer 28

the energy required to remove an electron from gaseous atoms

Question 29

What is the first ionisation energy?

Answer 29

the energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of 1+ ions

Question 30

What factors affect ionisation energy?

Answer 30

• nuclear charge (more protons = greater nuclear charge = stronger the electrostatic attraction)
• shielding (more shells = more shielding = outer electrons less attracted to nucleus)
• sub-shell the electron is being removed from (closer to nucleus = more attracted)

Question 31

What is the general trend of first ionisation energies across a period?

Answer 31

ionisation energies increase

Question 32

Why do first ionisation energies generally increase across a period?

Answer 32

• more protons in nucleus (greater nuclear charge)

- greater attraction between outer electron and nucleus

Question 33

What is the trend of first ionisation energies down a group?

Answer 33

ionisation energies decrease

Question 34

Why do first ionisation energies decrease down a group?

Answer 34

• more electrons so more shells
• more shielding
• outer electrons less strongly attracted to nucleus so are easier to remove

Question 35

What determines the chemical properties of an element?

Answer 35

electron configurations

Question 36

What is periodicity?

Answer 36

repeating patterns across a period

Question 37

Why do first ionisation energies decrease between group 2 and 3 elements?

Answer 37

lone electron in a p-orbital is being removed

group 3 element

Question 38

Why do first ionisation energies decrease between group 5 and 6 elements?

Answer 38

electron being removed is from a paired electron in a p-orbital so is experiencing repulsion
(group 6 element)