The Atom

Question 0

What does the Mass number tell us about an isotope?

Answer 0

The number of protons and neutrons in the nucleus

Question 1

What does the Atomic number tell us?

Answer 1

The number of protons in the nucleus

Question 2

Where are protons and neutrons found?

Answer 2

In the nucleus

Question 3

How would we calculate the number of neutrons in a isotope?

Answer 3

Mass number - Atomic number

Question 4

Give the relative charge and relative mass of protons, neutrons and electrons

Answer 4

Proton- charge +1, mass 1
Neutrons- charge 0, mass 1
Electrons- charge -1, mass 1/1840

Question 5

What did Ernest Rutherford discover?

Answer 5

Found that most of the mass and all of the positive charge was in a tiny central nucleus

Question 6

What did Henri Becquerel discover?

Answer 6

Radioactivity, showing that particles come from inside the atom, therefore atoms are divisible

Question 7

What did JJ Thompson discover?

Answer 7

The electron, and that is negatively charged, that all electrons from an atom are the same.

Suggested the precedes of protons to balance charge, suggested plum pudding model

Question 8

What did John Dalton discover?

Answer 8

Suggested elements were made of invisible atoms,

Same elements = same mass

Question 9

What did Robert Boyle discover?

Answer 9

Proposed there ewe substances that could be made simpler- chemical elements

Question 10

electrons are arranged in energy levels and sub-levels, what letters are given to the sub-levels?

Answer 10

s,p,d,f

Question 11

write an equation for the first ionisation energy of sodium?

Answer 11

Na(g) –> Na+(g) +e-

Question 12

what is the electronic configuration for vanadium? (periodic table needed)

Answer 12

1s2, 2s2, 2p6, 3s2, 3p6,3d3, 4s2

Question 13

which sub-shell fills first- 4s or 3d?

Answer 13

4s

Question 14

what is the maximum number of electrons held in each of the s, p ,d sub-shells?

Answer 14

s-2
p-6
d-10

Question 15

z for krypton is 36, what is the electronic configuration? (periodic table needed)

Answer 15

1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p6

Question 16

there are two isotopes of chlorine, Cl-35 (75%) and Cl-37 (25%), show that the R.A.M of chlorine is 35.5

Answer 16

(35 x 75) + (37 x 25)
____________________
100
=35.5

Question 17

how do we work out the relative atomic mass of an element?

Answer 17

add up (mass x abundance) for each isotope and then divide by total abundance
(mass x Abundance
__________________
total abundance

Question 18

what happens to first ionisation energies as we move left to right along the period? why?

Answer 18

it increases

because nuclear charge increases but shielding remains the same

Question 19

what is an atomic orbital?

Answer 19

a volume f space that an electron (or pairs of electrons) fill

Question 20

what is an energy level?

Answer 20

“a shelll”

a collection of electrons with similar energy. the first ‘shell’ contains 2, the second 8 and the third 18 electrons.

Question 21

when moving right to left across the period 3, what exceptions are there for ionisation energy?

Answer 21

Auminium- because the electron is being moved from3p, which has a slightly higher energy level than 3s.

Sulfur- because there are two electrons in one of the 3p orbitals and so there is repulsion between them

Question 22

what can we say about the spin of pairs of electrons?

Answer 22

paired electrons will have opposite spin

Question 23

what is the rule for electron pairing in orbitals?

Answer 23

electrons will fill in singly within the same sub-shell, before they pair (because they repulse each other)

Question 24

write the equation for the second and third ionisation energies of sodium

Answer 24

Na+(g) --> NA2+(g) + e- NA2+(g) --> NA3+(g) +e-

Question 25

define first ionisation energy

Answer 25

the energy required to remove one mole of electrons from one mole of atoms, in the gaseous state

Question 26

how are electrons removed from atoms?

Answer 26

ioniation, the atoms are hit with a beam of electrons from an electron gun

Question 27

what is an isotope

Answer 27

atoms of the same element, with the same number of protons and electrons, but a different number of netrons

Question 28

what does letter A stand for?

Answer 28

mass number

Question 29

what does the letter Z stand for?

Answer 29

atomic number

Question 30

define second ionisation energy

Answer 30

the energy required to remove one mole of electrons from one mole of atoms, with one positive charge, in the gaseous state

Question 31

when thinking about electrons what should we thnk

Answer 31

``` S- shielding A- attraction (to) N- necleus D- distance (of outer shell) E- elctrons ```

Question 32

what does ionic bonding happen between

Answer 32

metal and non-metal

Question 33

what properties do ionic compounds have

Answer 33

melting points strong force between oppositely charged ions molten when dissolved

Question 34

what is covalent bonding

Answer 34

sharing pairs of electrons between atoms

Question 35

what is another name for dative covalent bonding

Answer 35

co-ordinate bonding

Question 36

what is dative covalent bonding

Answer 36

a covalent bond where both electrons in the bond have been contributed by one species

Question 37

what happens in dative covalent bonding

Answer 37

an atom that is electron deficient, as it doesn't have a full outer shell, the atom that is donating the electrons has a pair of electrons not being used, called a lone pair

Question 38

what crystal structures conduct electricity? why?

Answer 38

al metallic, graphite | because they have delocalised electrons that are free to moe through the structure

Question 39

what effect do pairs of electrons both bonding and non-bonding have on each other

Answer 39

they repel

Question 40

what shape and bond angle would a molecule with only two bonding pairs of electrons in the outer shall have?

Answer 40

Linear | 180'

Question 41

what shape and bond angle would a molecule with only three bonding pairs of electrons in the outer shall have?

Answer 41

trigonal planar | 120'

Question 42

what shape and bond angle would a molecule with only four bonding pairs of electrons in the outer shall have?

Answer 42

tetrahedral | 109.5'

Question 43

what shape and bond angle would a molecule with only five bonding pairs of electrons in the outer shall have?

Answer 43

trigonal bipyramid | 90' and 120'

Question 44

what shape and bond angle would a molecule with only six bonding pairs of electrons in the outer shall have?

Answer 44

octahedral | 90'

Question 45

what shape and bond angle would a molecule with three bonding pairs and one lone pair have?

Answer 45

triangular pyramid | 107'

Question 46

what shape and bond angle would a molecule with two bonding pairs and two lone pairs have

Answer 46

v-shape | 104.5'

Question 47

what shape and bond angle would a molecule with four bonding pairs and two lone pairs have

Answer 47

square planar | 90'

Question 48

what repels more, bonding pairs or lone pairs

Answer 48

lone pairs

Question 49

what is ionic bonding

Answer 49

the electrostatic attraction between oppositely charged ions in a lattice

Question 50

what is an ion

Answer 50

a charged particle

Question 51

what charge do the ions of elements the groups 1,2,3,6,7 have?

Answer 51

``` 1= +1 2= +2 3= +3 6= -2 7=-1 ```

Question 52

what is metallic bonding

Answer 52

attraction between delocalised electrons and positive ions, in a lattice

Question 53

what is electro-negativity

Answer 53

the power of an atom to withdraw the electron density from a covalent bond

Question 54

what is meant by a polar bond

Answer 54

where the charge in a molecule is not symmetrical, so one area is slightly more positive and another slightly more negative

Question 55

what can we say about the polarity of bonds in elements

Answer 55

they are not polar

Question 56

what can we say about the polarity of bonds between different elements

Answer 56

they will be polar to different extents depending on the elements

Question 57

starting with the weakest, name the three types of intermolecular attraction

Answer 57

van der walls permanent dipole-dipole hydrogen bonding

Question 58

what is a single covalent bond

Answer 58

a shared pair of electrons

Question 59

what is a double covalent bond

Answer 59

two shared pairs of electrons

Question 60

how does the strength of a covalent bond compare with the strength of a hydrogen bond

Answer 60

covalent bonds are stronger

Question 61

what causes van der waals force

Answer 61

caused by instantaneous dipoles. these occur because in any instant electrons are not spread evenly and more will be in one area than another. this will, in that instant induce a dipole in its neighbour, leading attraction

Question 62

where do we find van der waals forces and what affects its strength

Answer 62

found in all atoms and molecules. the more electrons present, the bigger the force

Question 63

what causes permanent dipole- dipole force

Answer 63

attraction between molecules with permanent dipoles

Question 64

what effects the strength of permanent dipole-dipole force

Answer 64

the bigger he difference in electro-negativity between a bonding pair, the greater the dipole and so the greater the force

Question 65

what causes hydrogen bonding

Answer 65

when hydrogen is covalently bonded to NOF. the hydrogen can be shared between this and a lone pair on another molecule

Question 66

why does temperature not increase while a substance is melting or boiling

Answer 66

he energy is absorbed as the bond weakens

Question 67

what is the energy required to weaken the forces of attraction in a solid enough for a solid to turn into a liquid called

Answer 67

enthalpy change to fusion

Question 68

what are the four types of crystal structure

Answer 68

ionic, metallic, giant covelent , molecular

Question 69

what are ionic crystals held together by

Answer 69

intermolecular forces (van der waals, hydrogen, dipole-dipole) hold molecules together. covalent bonds hold atoms within the molecules together

Question 70

what are metallic crystals held together by

Answer 70

attractions between positive metal ions and a negative 'sea of delocalised electrons

Question 71

what are giant covalent (macromolecular) crystals held together by

Answer 71

covalent bonds

Question 72

what type of structure do the following crystals have? NaCl, Mg, Diamond, Graphite Iodine, Ice

Answer 72

``` NaCl- ionic Mg- metallic Diamond- Giant Covalent Graphite- Giant Covalent Iodine- Molecular Ice- molecular ```

Question 73

what is electron repulsion theory

Answer 73

each pair of electrons around an atom will repel all other electron pairs the pairs of electrons will take positions as far away from each other as possible

Question 74

what does macromolecular mean

Answer 74

a macromolecular structure is one in which large numbers of atoms are linked in the regular three-dimensional arrangement by covalent bonds

Question 75

why is the second ionisation energy of silicon is lower than the second ionisation energy of aluminium

Answer 75

Electron in Silicon is removed from a higher energy orbital/ more shielded

Question 76

Predict the element in period 3 that has the highest second ionisation energy

Answer 76

Na | Electron is removed from 2p

Question 77

explain why the ionisation energy of every element is endothermic

Answer 77

Energy needed to overcome attraction between electron and nucleus

Question 78

Suggest why the electronegativity of the elements increase from lithium to fluorine

Answer 78

The attraction to the nucleus increases The distance of the outer electron increases But shielding stays the same

Question 79

Explain how the current is generated in a mass spectrometer

Answer 79

Electrons transfer at the detector to the positive ion

Question 80

Identify the period two element, from carbon to fluorine that has the largest atomic radius. Explain answer

Answer 80

``` Carbon > fewest protons > smallest nuclear charge > least attraction between protons and electrons > weakest nuclear attraction > similar shielding ```

Question 81

State one reason why the first ionisation energy of rubidium is lower than the first ionisation energy of sodium

Answer 81

> Further from nucleus > from higher energy level > more shielding

Question 82

Why is there no hydrogen bonding between phosphine molecules

Answer 82

There is not a great enough difference in electronegativity

Question 83

In terms of structure and bonding, why does graphene have a high melting point

Answer 83

Covalent bonds are hard to break

Question 84

Why can a meal be hammered into different shapes

Answer 84

The layers can slide over each other making it malleable

Question 85

Suggest one reason why particles with the same mass and velocity can be deflected by different amounts in the same magnetic field

Answer 85

Different charges