Chapter 3- Periodicity Flashcards Preview

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Flashcards in Chapter 3- Periodicity Deck (69)
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1
Q

Which sub orbital is being filled on the far left of the periodic table?

A

s-orbitals

2
Q

Which sub orbital is being filled in the middle of the periodic table?

A

d-orbitals

3
Q

Which sub orbital is being filled on the far right of the periodic table?

A

p-orbitals

4
Q

What is the effective nuclear charge (ENC) determined by? (4 things)

A
  1. Distance from the nucleus to the outer-shell
    + largely depends by the # of shells
  2. Shielding by inner electrons
    + inner-shells reduce the effect of the nucleus due to repulsion
  3. Nuclear charge
    + greater the nuclear charge = the greater the attraction provided the # of shells and shielding = the same
  4. Sub-shell and electron pairing
    + when trends can’t be explained by above things = look at diff in sub-shells/ by electron pairing orbitals
5
Q

Atomic Radius

A

The dist. from the nucleus to the outer most electron

+ measured as half the dist. betw. 2 bonded atoms

6
Q

Descending a group the atomic radius___? and why?

A

+ INCREASES
+ Cuz the outer electrons in “NEW energy level”
= further from the nucleus
+ the increase in nuclear charge, cancelled out by increase distance and shielding

7
Q

Across a period the atomic radius___? and why?

A

+ DECREASES
+ Cuz the increase in “NUCLEAR CHARGE”
= as more protons r added while electrons = put in the same energy level

8
Q

Ionic Radius

A

Dist. betw. nucleus and outermost electrons of positive metal CATIONS or negative non-metal ANIONS.

9
Q

Descending a group the ionic radius___?

A

+ BOTH metal cations and non-metal anions = INCREASE in size

10
Q

Descending a group metal cations get___? and why?

A

+ SMALLER than their atoms!
+ Cuz they lose their outer-shell electrons
+ there’s ALSO reduction in shielding = a greater attraction of outer electrons to the nucleus!

11
Q

Descending a group non-metal anions get___? and why?

A

+ LARGER than their atoms!
+ Cuz they’ve gained electrons in their outer-shell
= increases the repulsion between electrons = size gets bigger!

12
Q

Across a period the ionic radius___? and why?

A

+ REDUCTION in size

= due to the increase in protons (nuclear charge) whilst all the ions hv. the same electronic configuration.

13
Q

Descending a group the ionisation energy___? and why?

A

+ DECREASES
+ outer shell electrons easier to remove = further and more shielding from the nucleus due to the increase in atomic radius as the atoms hv. more shells!

14
Q

Across a period the ionisation energy___? and why?

A

+ generally INCREASES
+ cuz the increase in protons (nuclear charge) = increase attraction form outer-shell electrons which are in the same energy level.

15
Q

Electronegativity

A

The ability of an atom to attract a pair of electron towards itself within a COVALENT bond.

16
Q

Descending a group the Electronegativity ___? and why?

A

+ DECREASES
+ cuz the bonding electrons = further and more shielded from the nucleus due to an increase in the atomic radius as the atoms have more shell.

17
Q

Across a period the Electronegativity ___? and why?

A

+ INCREASES
+ cuz the increase in # of protons (nuclear charge) = causes an increase in the attraction for the bonding electrons, which are in the SAME energy level.

18
Q

Most electronegative elements?

A

FON

19
Q

Electron Affinity

A

The energy change when ONE mole of electrons are ADDED to one mole of GASEOUS atoms.

20
Q

First electron affinity is exo or endothermic? and why?

A

Exothermic

+ cuz energy is RELEASED when an electron bonds to an atom.

21
Q

Descending a group the electron affinity___? and why?

A

Generally becomes LESS negative. = decease in energy released!
+ cuz the incoming electrons = further and more shielded from the nucleus due to the increase in atomic radius as the atom has more shells.

22
Q

Across a period the electron affinity___? and why?

A

Generally become MORE negative = increase in energy released!
+ cuz the increase in the number of protons (nuclear charge) causing an increase in attraction for the extra electron.

23
Q

Metals have LOW___ and ___?

A

Ionisation energies and electronegativities

24
Q

Metals form compounds with non metals by by what type of bonding?

A

Ionic bonding = losing electrons to from + cations (pawsitive! >

25
Q

Properties of metals (4)

A
  1. Solid at room temperature (except for mercury)
  2. High m.p and b.p
  3. Malleable and Ductile
  4. Good conductors of both heat and electrocity in solid state
26
Q

Are the elctronegativites and ionisation energy in non-metals high or low?

A

HIGH!

27
Q

What do the physical properties of non-metals depend on?

A

How the covalent bonds join atoms of the element.

28
Q

If covalent bonds in non-metals give rise to molecules (small # of atoms joined) what state are they in?

A

+ Gas
+ Liquid
+ Low m.p solids

29
Q

If covalent bonds produce a 3D network what state are they in?

A

High m.p solids

30
Q

Do covalent structures conduct electricity?

A

No

Except for graphite (exception with regards to hardness and conductivity )

31
Q

Metal oxides?

A

are BASIC

32
Q

Metal oxides react w/ water to form?

A

Their hydroxides

33
Q

Metal Oxides + Acid → ? + ?

A

Salt + Water

34
Q

Is Aluminium basic or acidic?

A

Neither = It’s Amphoteric
→ Reacts and dissolves in both Acids and Bases
(displays properties of metallic and non-metallic oxides)

35
Q

Silicon dioxide = though has little acid-base activity → does show some acidic properties by?

A

Slowly dissolving in hot conc. alkalis to form silicate.

36
Q

Non-metal oxides?

A

are ACIDIC

37
Q

What oxides contribute to acid rain?

A

Sulfur and nitrogen oxides

38
Q

What effect does acid rain have on aquatic life?

A

Makes lake water too acidic for aquatic life to survive

39
Q

How does acid rain damage plants?

A

+ Damage leaves and roots by causing enhance leaching of metal ions from soil
+ esp. Mg2+ = essential for chlorophyll production

40
Q

If the metal ions that are leached from the soil enter water supplies what is the dangers?

A

+ Negative impact on human health

+ Al3+ linked to increased risk of Alzheimer’s disease

41
Q

How does acid rain damage infrastructure?

A

+ Enhance corrosion of limestone

+ Increase the rate at which iron and steel rust because of the low pH

42
Q

Why do elements in the same group of the periodic table have similar properties?

A

Same # of electrons in the outershell (valence shell)

43
Q

Properties of Alkali metals (Li Na K Rb Cs)

A

+ Soft malleable metal and low m.p ( because each atom can ONLY contribute “1” electron to metallic bonding = less strong than for other metals)
+ low density = because they are the largest atoms in their period of p. table

44
Q

Descending the group of Alkali metals what happens to the hardness and m.p?

A

+ Gets softer
+ m.p decreases
As the attraction betw/ nucleus and outer electrons decrease as a result of the increase in size of atoms

45
Q

Alkali metals always form what numbered ions?

A

+1 ions (cuz only 1 electron in outershell)

46
Q

Why do Alkali metals Tarnish rapidly?

A

Because they are chemically really reactive

+ They react w/ oxygen to form oxides on exposure to oxygen

47
Q

In excess oxygen what happens to Alkali metals?

A

React further to produce oxides containing a higher proportion of oxygen

48
Q

What compounds to Alkali metals create when reacted w/ Halogens?

A

Ionically bonded compounds

49
Q

Alkali metals + water → ? + ?

A

Metal hydroxide + H (g)

VERY SPONTANEOUSLY

50
Q

What do Halogens exist as?

A

Diatomic molecules (F2, Cl2 etc.)

51
Q

Descending group what happens to physical state?

A

Gas (F and Cl) → Liquid (Br) → Solid (I = forms purple vapour when heater)

52
Q

Why are halogens really electronegative?

A

Require just “1” electron to fill outershell

→ They react readily to gain electrons and form single charged ions

53
Q

What happens to reactivity down a group?

A

Decreases
→ cuz ease at which they gain electrons decrease = cuz electrons gained are further away from nucleus = less strongly attracted

54
Q

Are halogens soluble in water?

A

Slightly = cuz they’re non-polar

→ so only bond to polar water molecules by dispersion forces

55
Q

What colour do:
+ Conc. solution of Cl
+ Conc. solution of Br give?

A

+ Green tinge

+ Darken from yellow → orange → brown as conc. increases

56
Q

In non-polar solvents (s.a Hexane) what colour soln does Iodine form?

A

Violet

57
Q

In polar solvents (s.a water/ ethanol) what colour soln does Iodine form?

A

Brown

58
Q

In aqueous solution halogens react to form what solution?

A

Slightly acidic soln
w/ compound HOX (X halogen)
X2 + H2O → H+ (aq) + X- (aq) + HOX (aq)

59
Q

What agent does HOX act as? and why?

A

Oxidising agent = cuz it can readily donate its Oxygen to other substances

60
Q

What does Chloric acid (HOCl) do to coloured dyes?

A

Oxidize them to colourless products

61
Q

Chloric (I) acid and conjugate base = Choride (I) ion (OCl-) can be useful because of what properties?

A

+ Used as bleaches (e.g for paper)

+ Used as disinfectant (e.g for pool)

62
Q

Halogens act as what agents?

A

Oxidising agents as readily gains electrons

63
Q

Descending the group what happens to the size of the atoms?

A

Increases = attraction betw/ nucleus and electrons become less → become LESS powerful oxidising agents

64
Q

Higher halogens will do what to the lower halogens?

A

Displace it from its salt by removing a valence electron

65
Q

Transition elements

A

Elements that have a partially filled d-subshell in the elements of in 1 of its common oxidation state

66
Q

Properties of Transition elements (5)

A

1) Variety of oxidation states
2) ability to form complex ions
3) Catalytic activity
4) Magnetic properties
5) Form colored compounds

67
Q

Why does the successive ionisation energies of transition metals not increase largely?

A

Cuz 3d and 4s electrons have similar energies

68
Q

What do the oxidation states of transition metals depend on?

A

Redox environment

→ The presence of species that readily gain or lose electrons

69
Q

Except for Sc = all transition metals have what oxidation state?

A

+2

→ Corresponds to loss of 4s electrons