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Atomic Structure & Bonding Flashcards

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1
Q

Periods and Groups tell us what about the electronic configuration of an atom?

A

Periods - The number of electron shells/levels
Groups - The number of electrons on it’s outer shell

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2
Q

Why are covalent bonds strong?

A

The shared electrons are attracted to the nucleus of both atoms

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3
Q

Why is the melting point of ionic lattices high?

A

A large amount of energy is needed to overcome the strong electrostatic forces of attractions that produce the bonds.

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4
Q

Why can ionic lattices conduct electricity when molten or in in water but not solid?

A

When solid, the ionic lattice has a fixed arrangement, meaning the negatively charged IONS are not free to carry the flow of charge. But as a liquid, the IONS are free to move around to conduct electricity.

(MUST NOT SAY ELECTRON. THEY ARE IONS)

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5
Q

What is the difference between intermolecular forces, and intramolecular forces?

A

Intermolecular - forces between molecules
Intramolecular - forces within molecules

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6
Q

Why do small covalent substances have low melting points?

A

Their intermolecular forces are weak, due to the fact they have a small mass and are only held by gravity. Because they are weak, it takes little energy for these intermolecular forces to be overcome.

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7
Q

Why are simple covalent substances unable to conduct electricity?

A

Covalent substances do not contain delocalised/free electrons, and have no charged particles. This inhibits it’s ability to conduct electricity.

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8
Q

Why are some covalent substances solids at room temperature/have high melting points?

A

Some covalent substances have large particles and therefore a stronger intermolecular bond due to gravity. These strong intermolecular bonds take more energy to break, therefore requite higher temperatures.

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9
Q

List some properties of giant covalent structures.

A
  • no formula (the structure can be of any size)
  • high melting + boiling points (due to strong covalent bonds)
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10
Q

Why are there no intermolecular forces in giant covalent structures like diamond?

A

The giant covalent structure only contains one molecule/structure. There cannot be intermolecular forces with only one molecule present.

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11
Q

What is metallic bonding?

A

Chemical bonds between only metals that are formed by the strong electrostatic forces of attraction between positive metal ions and a sea of delocalised electrons.

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12
Q

What is covalent bonding?

A

Chemical bonds between only non-metals where pairs of electrons are shared between the atoms.

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13
Q

What is ionic bonding?

A

Chemical bonds between metals and non-metals which are formed through the strong electrostatic forces of attraction between the negatively charged non-metals and the positively charged metals.

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14
Q

What is the average size of an atom?

A

0.1 nanometres or 1 x 10⁻¹⁰ m

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15
Q

What is the molecular arrangement of graphite, graphene and diamond?

A

Graphite - hexagonal fullerene of sheets in layers. There are free electrons.
Graphene - Same as graphite but without intermollecular forces - it’s one molecule thick. There are free electrons.
Diamond - One large molecule, where one carbon atom bonds to 4 other carbon atoms to make the regular tetrahedral structure. There are no free electrons.

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16
Q

What is a fullerene?

A

An arrangement of hollow carbon particles with hexagonal rings bonded together covalently.

17
Q

Why are nano-particles useful?

A
  • They have a high volume to surface area ratio, and therefore smaller amounts are needed
  • They can change the properties of the material
18
Q

What are nanoparticles used for?

A
  • in medicine
  • as catalysts
  • in electronics (computer chips)
  • cosmetics
  • deodorants (due to antimicrobial properties)
19
Q

How is mass number calculated?

A

number of protons + number of neutrons

20
Q

What does the top number of an element show? And what does the bottom number?

A

Top number - MASS NUMBER (number of protons AND neutrons)
Bottom number - atomic number (number of protons)

DO NOT CALL IT ATOMIC MASS IN AQA. IT IS THE MASS NUMBER.

21
Q

What is a noble gas?

A

A Group 0 Element,
- inert (unreactive due to their full outer shell)
- monatomic (does not form mollecules, rather exists as atoms)
- colorless
- low boiling points (which get higher as you go down the group)

22
Q

WE GOT UP TO HERE W/ THE FLASHCARDS

What is this reaction and why does it occur?

hydrogen chloride + flourine —> hydrogen flouride + chlorine

(wink wink if u get my breaking bad reference)

A

Displacement reaction
Flourine is more reactive than chlorine and so displaces chlorine to produce hydrogen flouride

(wink wink if u get my breaking bad reference)

23
Q

What is a halogen?

A

A group 7 element that is
- highly reactive (due to it having 7 electrons on its outer shell)
- diatomic mollecules
- less reactive as you go down the group
- higher melting and boiling points as you go down the group
- larger relative molecular mass as you go down the group

24
Q

Why are halogens less reactive further down the periodic table?

A
  • They have more electron shells, and therefore a larger distance between the outer shell electrons and the nucleus.
  • So the attraction between the nucleus and the electron (that will be gained through ionic bonding) decreaces
25
Q

Why does reactivity increace as you go down the alkali metals?

A
  • As you go down the group, there is a weaker attraction between the outer electron and the nucleus because they are further apart
  • The outer electron is also sheilded from the nucleus by the internal energy shells
  • This makes it easier to loose the electron, which means it is more reactive.
26
Q

What is an alkali metal?

A

A group 1 element that,
- is soft (can be cut with a knife)
- have relatively low boiling points and densities
- reacts rapidly with water, oxygen and chlorine
- as you go down the group, reactivity increaces

27
Q

What are the reactions of alkali metals?

A
  • When reacted with chlorine, a metal chloride is produced. This dissolves in water and produces a colorless solution
  • When reacted with oxygen, a metal oxide is produced which makes the metal appear dull rather than shiny
  • When reacted with water, a hydrogen and metal hydroxide is produced, which is an aqueous, alkali solution. The energy released from the reaction is great enough to melt the metal.
28
Q

Properties of transition metals

A
  • less reactive compared to g1 elements
  • high boiling point (except mercury)
  • strong and hard
  • dense
  • can form ions with different positive charges (e.g, 2+, 3+ 4+)
  • can form colored compoundes (e.g, Iron (III) oxide is red)
  • can be used as a catalyst
29
Q

Why doesn’t pure water conduct electricity?

(2 marks)

A

Because it has no delocalized electrons (1) or ions to carry the charge. (1)

30
Q

WE GOT UP TO HERE W/ THE FLASHCARDS

What are…
Coarse Particles
Fine Particles
Nanoparticles?

A

Coarse Particles - Dust, PM₁₀, 2,500 - 10,000 nm in diameter
Fine Particles - Particulate matter, PM₂.₅, 100 - 2,500 nm in diameter
Nanoparticles - 1-100 nm in diameter

31
Q

What is the relationship between surface area : volume and particle size?

A

As the particle decreaces by 10x in size,
It increaces by 10x in surface area : volume ratio.

32
Q

Why is only a smaller amount of nanoparticles needed of a substance?

A

Because nanoparticles are so small compared to normal particles, they have a high surface area to volume ratio.
With this higher surface area, a smaller amount is needed to fuffil its function.

33
Q

Describe the Advantages and Disadvantages of using Nanoparticles

A

Advantages
1. Changes the properties of a material
2. High surface area, so effective catalysts
3. Changes the original properties of the material, so versatile
4. Transparency in sunscream

Disadvantages
1. Can enter bloodstream when applied onto skin
2. We do not yet know the long-term effects
3. Large surface area causes some nanoparticles to be reactive and explosive
4. Can easily become airborne and damage the lungs

34
Q

Outline the steps of fractional distillation.

A
  • The round bottom flask is heated (e.g, with a bunsen burner). The substances in the mixture begin to evaporate.
  • The substance with a lower boiling point will evaporate more easily
  • When the substances hit the fractionating collum, they condense back into the flask. This repeats and increases the amount of the substance with a lower boiling point
  • As they pass the themometer, the temperature rises
  • Once this reaches the boiling point of the substance with a lower boiling point, only that substances goes through the condenser and drips out into the conical flask as a pure substance.
  • This is repeated, but with a higher boiling point for the other substances within the mixture.
35
Q

How did Mendeleev arrange the periodic table?

(3 points)

A
  • He put it in order of increasing atomic weight (now known as mass number)
  • He then switched around the orders of the elements so that elements with similar properties could be grouped together
  • He then left gaps in his periodic table, as he realised there were elements that had not yet been discovered.
36
Q

What are the key differences between Mendeleev’s periodic table, and our modern one?

A
  • Mendeleev had ordered it in terms of atomic weight (mass number) as atomic number (the number of protons) had not yet been discovered.
    [This meant that some elements would be in the wrong order, due to the presence of isotopes]
  • The modern periodic table contains group 0 elements (noble gasses). These had not been fully discovered when Mendeleev made his periodic table.
36
Q

What did Döbereiner and Newlands do to order the periodic table?

A

Döbereiner
- Triads
- He noticed that elements with similar properties often came in groups of 3 (e.g, chlorine, bromine, iodine are all reactive non-metals)
Newlands
- Law of Eighths
- He noticed that when you order the elements in terms of increasing atomic weight (mass number), every 8th element would react in a similar way

36
Q

Why does reactivity increace as you go down the alkali metals?

A
  • As you go down the group, there is a weaker attraction between the outer electron and the nucleus because they are further apart
  • The outer electron is also sheilded from the nucleus by the internal energy shells
  • This makes it easier to loose the electron, which means it is more reactive.

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