Atomic Structure And The Periodic Table

Question 1

mass of an electron

Answer 1

1/1840

Question 2

mass number

Answer 2

total number of particles in the nucleus

Question 3

atomic number

Answer 3

number of protons in the nucleus

Question 4

number of neutrons

Answer 4

mass number - atomic number

Question 5

isostopes

Answer 5

atoms of the same type with a different number of neutrons

Question 6

relative atomic mass

Answer 6

the average mass of an atom of an element, relative to 1/12th the mass of as carbon-12 atom

Question 7

relative isotopic mass

Answer 7

the mass of one mole of an isotope of the element expressed on a scale on which one mole of the atoms of the C-12 isotope has a mass of exactly 12 units.

Question 8

relative molecular mass

Answer 8

Average mass of a molecule of a substance relative to 1/12th the mass of a carbon 12 atom

Question 9

determining relative atomic mass from mass spectrometer

Answer 9

1. the sample is vaporised
2. the sample is ionised
3. ion is accelerated by an electric field
4. ions pass through the magnetic field and are deflected
5. ions are detected and recorded

Question 10

the size of the peaks in mass spectra

Answer 10

number/abundance of each type of ion

Question 11

chlorine mass spectra

Answer 11

chlorine has two isotopes at mass 35 and mass 37, the height of 35 trace is three times that of 37 so its three times more abundant

Question 12

first ionisation energy

Answer 12

energy required to remove one electron from one moles of gaseous atoms to produce one mole of 1+ gaseous ions

Question 13

attraction of the electron to the nucleus

Answer 13

· The charge on the nucleus – the higher the charge, the greater the attraction
· The distance from the nucleus - the greater the distance, the less the attraction
· Shielding from inner electrons – the more inner electrons, the less the attraction.

Question 14

reasons for first ionisation energy to increase across a period

Answer 14

• same number of shells
• increased nuclear charge
• greater attraction to the nucleus

Question 15

reasons for first ionisation energy to decrease down a group

Answer 15

• increasing number of shells
• greater shielding
• decreased attraction to the nucleus

Question 16

second/successive ionisation energy

Answer 16

The energy required to remove one electron from each ion in one mole of gaseous ions with a single positive charge producing one mole of gaseous ions with two positive charges

Question 17

in shell one what are the sub shells

Answer 17

1s2

Question 18

in shell two what are the sub shells

Answer 18

2s2 2p6

Question 19

in shell three what are the sub shells

Answer 19

3s2 3p6 3d10

Question 20

orbital

Answer 20

The area occupied by an electron wave

Question 21

s orbital

Answer 21

2 electrons

Question 22

p orbital

Answer 22

6 electrons in 3 orbitals

Question 23

d orbital

Answer 23

10 electrons in 5 orbitals

Question 24

how do electrons fill subshells

Answer 24

singly but then pair up and two electrons in the same orbitals have to have opposite spins

Question 25

how does a flame test work

Answer 25

electrons in the sodium atoms gain energy from the heat and jump to a higher energy level. They then drop back down to a lower energy level giving out energy, this time in the form of visible light. This is known as emission.

Question 26

group 4 bonding

Answer 26

tend to form giant covalent structures, although the elements towards the bottom of the group are metallic. Lead and tin are metallic because their large atoms have electrons a long way from the nucleus with a great deal of inner shielding which means they can be released quite easily

Question 27

group 5, 6, 7 bonding

Answer 27

generally have simple covalent structures, although again at the bottom of the group the elements become more metallic.

Question 28

group 8 bonding

Answer 28

noble gases, having complete electron shells are monatomic

Question 29

periodicity

Answer 29

repeating pattern across different periods

Question 30

periodicity in period 2, 3 metallic

Answer 30

metallic and boiling points increase as you go along

• the positive charge on the metal ion increase
• greater charge density
• The number of electrons in the delocalized region increases
• the attraction between the ion and the delocalized electron region increases.

Question 31

periodicity in period 2, 3 giant molecular

Answer 31

melting and boiling points are at their highest as vast numbers of strong covalent bonds must be broken to release the atoms.

Question 32

periodicity in period 2, 3 simple molecular

Answer 32

melting and boiling points are low

• intermolecular forces are weak
• roughly relative to the size of the molecules
• the noble gases have the lowest melting points as they are monatomic.