Atomic Structure

Question 1

Name 3 sub atomic particles, their location, mass and charge

Answer 1

Protons, nucleus, 1, +1
Neutrons, nucleus, 1, 0
Electrons, electron shells around the nucleus, 1/2000, -1

Question 2

Define atomic number

Answer 2

Number of protons in an atom
Defines element

Question 3

Define mass number

Answer 3

Number of protons and neutrons in an atom
Defines isotope

Question 4

Does atomic number or mass number go at the top

Answer 4

Mass number

Question 5

Define an isotope

Answer 5

Atoms with the same number of protons/atomic number but different number of neutrons/mass number

Question 6

Define relative isotopic mass

Answer 6

The average mass of one atom in a sample of one isotope of an element only on a scale where one atom of C-12 is 12 units exactly

Question 7

Define relative atomic mass

Answer 7

The average mass of one atom in a naturally occurring sample of an element on a scale where one atom of C-12 is 12 units exactly

Question 8

Which formula mass should be used for giant structure compounds

Answer 8

RFM
Units g/mol

Question 9

Describe the process of mass spectronomy

Answer 9

Sample vaporised
Particles pos ionised by electron gun (knocks of electrons)
Positive ions accelerated
Pass through neg charged grid
Curved mag field (curved mag poles)
Deflect smallest/most charged ions easiest
Detector has a m/z ratio
Records no.ions/ratio
Ratio is changed to count different partciles

Question 10

Describe a mass spectronomy graph

Answer 10

Y axis: relative intensity
X axis: m/z (z usually 1 but CHECK)
Can be 2 clusters of peaks (parent ions and fragments)
Eg. Ionised Cl2 molecules and fragmented Cl molecules

Question 11

Describe how to calculate RAM
Eg. Cl

Answer 11

(Relative intensity x mass number) + (“”) / 100

Question 12

Describe how to calculate relative abundance of isotope
Eg. Chlorine

Answer 12

Fragments: read straight of graph, make ratio
Parent ionised molecules: all combinations, combined mass number, x relative abundances of atoms, combine any same, find probability as a percentage

Question 13

State 2 things that can happen when an atom gains energy

Answer 13

Speed up
Excitation

Question 14

What is a ground state atom formation

Answer 14

Most stable, normal arrangement o electron
Only ever 1
Electrons held in place by ESA with nucleus

Question 15

What is excitation

Answer 15

Electron moves away to a shell further from the nucleus
Energy absorbed to overcome ESA
Many different excited states
Larger distance = layer excitation
Unstable

Question 16

What is relaxation

Answer 16

Electrons drop back down from excited state
Release energy, photons of light (EMR)
Shine through, series of lines, match light of a specific wavelength

Question 17

What binds an electron the nucleus

Answer 17

Fixed energy caused by ESA between neg charged electron and pos charged nucleus

Question 18

Describe the Lyman series on a line emission spectra graph

Answer 18

N=1
High energy
Low wavelength
UV spectrum
Not visible

Question 19

Describe the Balmer series on a line emission spectra graph

Answer 19

Only visible series
Followed by further relaxations

Question 20

Describe the Paschen and Brackett series on a line emission spectra graph

Answer 20

Infrared spectrum
Non visible
Low energy
High wavelength
Followed by further relaxations

Question 21

What do arrows on a line emission spectra graph represent

Answer 21

Possible relaxations
Large length = large energy lost

Question 22

What is an electron address

Answer 22

Exact position in cloud of electrons
Principal shell: size of region
Sub shell: shape of region
Orbital: orientation of region
Spin: up/down

Question 23

Describe the patterns of sub shells and principal shells

Answer 23

N=3 has 3 sub shells
S, p, d, f

Question 24

What is an orbital

Answer 24

A region within an atom that can hold up to 2 electrons with opposite spins

Question 25

Describe the shape, number of orbitals and electrons in each subshell

Answer 25

S, spherical, 1, 2 P, bow tie, 3, 6 D, clover, 5, 10 F, -, 7, 14

Question 26

Describe electron configuration, shortcuts, exceptions and what they show

Answer 26

2s*2 PS=2 SS=s No.es=2 4s precedes 3d Shorten using noble gases [Ne] Exceptions: Cu,Cr (4s*1) They determine chemical properties of an element

Question 27

State 2 rules for electrons in boxes

Answer 27

Fill sub shells stay before pairing up 2 electrons in same box must spun in opp direction

Question 28

Describe the ‘block’ of elements

Answer 28

Block indicates subshell outer electron is in S block= G1,2 + He,H D block= transition metals P block= G3-0 F block= ones at bottom

Question 29

Describe ionisation

Answer 29

Orbitals get closer together Eventually converge Give electrons energy Pass convergence Electron lost Atom becomes ion Always an endothermic reaction (+Kj/mol)

Question 30

Define ionisation energy

Answer 30

Minimum energy required to remove 1 electron from each atom in a mole of atom sin the gas state Units=Kj/mol

Question 31

Describe successive ionisations

Answer 31

Atoms with more than one electron (not H) Each ionisation removes 1 atom IE increases arch time

Question 32

Describe patterns in an IE graph of one atom

Answer 32

Large increase between principal shells (decrease shielding, despite increased ESA) Small increase across principal shell (shielding approx constant, decrease ESR)

Question 33

What 2 forces determines the binding of an electron to an atom

Answer 33

ESA between neg e and pos nucleus ESR between neg electrons

Question 34

Define shielding

Answer 34

Reduction in ESA between e ad atom nucleus due to es in inner shells blocking the full force

Question 35

Name 4 patterns in first IE graphs

Answer 35

Increases mostly across period Decreases between periods Decreases don a group 2 small decreases across a period

Question 36

Why does IE mostly increase across period

Answer 36

Increase no.protons/nuclear charge Increase ESA Es held tighter Despite shielding approx constant Decrease in steepness/period

Question 37

Why does IE decrease between periods

Answer 37

Ionise from new outer principal shell Increase shielding Es held looser Despite increased nuclear barge/ESA

Question 38

Why does IE decrease down a group

Answer 38

increased shielding Increased distance from nucleus decreased ESA Despite increased nuclear charge/ESA

Question 39

Why does IE decreased between group 2 and 3 element

Answer 39

Ionising from a new p subshell Looser bound than s Further from nuclei, decreased ESA

Question 40

Why does IE decrease between group 5 and 6

Answer 40

Ionise from doubly occupied p orbitals Increased ESR

Question 41

Define periodicity

Answer 41

A property that follows a recurring pattern through the periodic table

Question 42

Name 3 periodicity patterns

Answer 42

Atomic radius Mp/bp Electronegativity

Question 43

Explain periodicity of atomic radius

Answer 43

Decreases across period, increased nuclear charge/ESA, despite approx constant shielding, es held tighter Increases between periods, new principal shell, increased shielding, despite increased nuclear charge/ESA Cations < atom < anion

Question 44

Explain periodicity of melting point/boiling point

Answer 44

High values: giant structure Low values: simple molecular, lack of bonding Bp is the same but slightly higher values