Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NCEA Level 1 > Chemistry - 90933 > Flashcards

Chemistry - 90933 Flashcards

1
Q

Smallest part of an element that can take part in a chemical reaction

A

Atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mass of protons, electrons, neutrons on atomic scale

A

Proton 1. Neutron 1. Electron 0.0005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which atom contains no neutrons

A

Hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Mass number

A

No. protons and neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Atomic number

A

No. protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When are H, He, Li and Be most stable

A

When they lose electrons to have 2 or 0 in total.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Group (periodic table)

A

Vertical columns on the table, all atoms have same amount of valence electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Periods (periodic table)

A

Horizontal rows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Gradual change from metallic to non-metallic elements across each row of periodic table. T/F?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Physical properties

A

Properties that identify a substance but do not include the chemical reactions of a substance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which common metal is liquid at room remp

A

Mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Density of metals

A

Generally above 3 g mL-1. Sodium and lithium are less than 1 g mL-1 (therefore float on water).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lustre

A

How well a substance shines/reflects light. Metals can have high lustre. Non-metals tend to be dull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Electrical conductivity

A

Measure of how easily electricity flows thorugh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Thermal conductivity

A

Measure of how easily heat energy passes through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Malleability

A

Measure of how easily a substance can be beaten or pressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ductility

A

Measure of how easily a substance can be drawn into a wire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Hardness

A

Measure of how easily a substance can be scratched or cut. Many metals are too soft but can be made into an alloy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why might a metal with high lustre appear dull

A

It might have reacted with oxygen or water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Atoms of metals for a close-packed ____, which results in a hard, ____ structure.

A

Lattice. Crystalline.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Can the weakly held valence electrons of metals move easily through the metal lattice structure?

A

Yes. And the metallic bond results from the attraction between the positive metal ions and the ‘sea’ of valence electrons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why do some metals have a high melting point

A

The ‘sea’ of electrons acts as a ‘glue’ binding the positive ions closely together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why do metals have high electrical and thermal conductivity

A

Because of the mobility of valence electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why are metals malleable and ductile

A

The layers of atoms in the lattice can move over each other and deform without breaking.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How are alloys formed

A

By mixing 2 or more molten metals and allowing them to cool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Melting point of alloys

A

Indistinct, given they are 2 or more different metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why are alloys used

A

Because the properties of 2 or metals combined is more useful than one of the metals alone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why are alloys hard

A

A small amount of metal atoms replace a number of atoms in the lattice of the parent metal, reducing the ability for atoms to move over each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Properties of brass

A

Copper and zinc. Less corrosive than copper and retails electrical conductivity of copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Properties of bronze

A

Copper and tin. Attractive coating that lasts a long time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Properties of solder

A

Tin and lead. Melts at lower temp and can bond with many metals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Properties of pewter

A

Tin and lead, and small amounts of copper and antimony. Harder than lead and does not release lead.

33
Q

Properties of duralumin

A

Aluminium and magnesium. Higher strength but low density.

34
Q

Properties of cupronickel

A

Copper and nickel. Harder and longer lasting than nickel.

35
Q

Steel

A

An alloy that contains 0.5-2% carbon as well as iron and other metals (depending on need). High tensile strength and resist corrosion.

36
Q

Uses of aluminium

A

Window frames, ranchsliders, ladders, aeroplane bodies, small boats, caravans, drink cans, tennis racquets etc

37
Q

Uses of copper

A

Wiring, hot-water piping, roofing.
Bronze (alloy) - statues.
Brass (alloy) - electrical terminals, marine/household fittings.
Cupronickel (alloy) - gold/silver coins.

38
Q

Uses of iron ally (steel - actual iron is difficult to obtain and is soft)

A

Cars/vehicles/trains/ships etc.
Reinforced concrete, bridges, scaffolding.
Large and small containers.
Tools/instruments - hammers, cutlery, forceps, drills.

39
Q

Uses of zinc

A

Protection of steel (galvinised).
Battery casings.
Brass alloy (with copper)

40
Q

Used of lead

A

Roofing, solder alloy (with tin)

41
Q

Uses of magnesium

A

Duralumin alloy for airframes and car wheels.

In flares - bright, white light.

42
Q

Uses of silver and gold

A

Decoration/jewellery (high lustre/colour)/

Gold as alloys to produce harder (less yellow) gold.

43
Q

Chemical reactivity

A

Properties that allow metal atoms to undergo chemical reaction

44
Q

Reactivity is determined by

A

The ease with which the valence electrons are removed from the atom (positive ion formed)

45
Q

Order of reactivity of some metals

A

Lithium > sodium > calcium > magnesium > aluminium > zinc > iron > lead > (hydrogen) > copper > silver > gold

46
Q

Oxidise

A

Metals oxidise at different rates depending on their reactivity.

47
Q

Word equation for oxidation reaction

A

Metal + oxygen -> metal oxide

48
Q

Can gold and silver react with oxygen under any conditions?

A

No

49
Q

Can metals react with water/steam?

A

Yes, depending on the metal (reactivity) (metal + water -> metal hydroxide + hydrogen gas)
e.g lithium + water -> lithium hydroxide + hydrogen (and the heat produced can be enough to ignite the hydrogen)

50
Q

Are non-metals good conductors of electricity and heat, and do they have lustre, malleability and ductility?

A

No, there are exceptions though.

51
Q

Allotrope

A

Allotropes are different forms of the same element. Different bonding arrangements between atoms result in different structures with different chemical and physical properties. Allotropes occur only with certain elements, in Groups 13 through 16 in the Periodic Table.

52
Q

Percentage O2 in atmosphere

A

21%

53
Q

Percentage O2 in earth’s crust

A

50%

54
Q

Do most elements react with O2

A

Yes, most react, causing heat and light.

55
Q

Ozone

A

Allotrope of oxygen (O3). Colourless gas with strong smell.

56
Q

Is ozone beneficial or harmful?

A

Harmful to animals’ respiratory tracts. Beneficial in keeping UV rays from reaching Earth’s surface.

57
Q

Uses for ozone

A

Purify and disinfect air and water. More effect than chlorine and other oxidising agents, and leaves no harmful or odourous by-products.

58
Q

How is carbon usually found?

A

In a combined form. E.g calcium carbonate, carbon dioxide, organic molecules, coal.

59
Q

Well known allotropes of carbon

A

Graphite, diamond, fullerenes

60
Q

Graphite vs diamond bonding

A

Graphite: 3 electrons per C atom covalently bond, the 4th bonds weakly to other C atoms in layers above and below it.
Diamond: strong 3-D network of covalent bonds with all 4 electrons

61
Q

Why does graphite feel slippery and why is it a good conductor of electricity?

A

Slippery because the layers of hexagonal rings can slide over each other.
Good conductor because the loose electron can move around.

62
Q

Fullerene

A

Graphite-like structure of C but with pentagonal and heptagonal structures as well as the normal hexagonal ones.

63
Q

Two examples of structures in the fullerene family

A

Buckminsterfullerene (buckyball) (C60) and carbon nanotube (buckytube)

64
Q

Sulfur + oxygen

A

Sulfur dioxide

65
Q

Uses of sulfur

A

Production of sulfuric acid, which has many uses.

66
Q

Process used to produce pure H2SO4

A

Contact Process (uses a catalyst)

67
Q

Properties of sulfuric acid

A

Acidic when in aqueous solution. Ionises completely in water. Releases H gas when reactive metals are added to it. Neutralises bases to form salts. Dehydrates other chemical substances. Oxidises metals and non-metals. Sulfonates organic molecules (to make detergents). Catalyst in many reactions.

68
Q

Uses of sulfuric acid

A

Production of fertilisers. Manufacture of chemicals (e.g HCl, nitric acid, sulfate salts, synthetic detergents, dyes, pigments, explosives, drugs). Petroleum refining. Cleaning metals. Manufacture of synthetic fibres. Battery acid.

69
Q

Is chlorine reactive

A

Yes, very

70
Q

How is chlorine commonly found

A

As sodium chloride

71
Q

How is hydrogen chloride produced?

A

Hydrogen and chlorine are heated form HCl, which is highly soluble.

72
Q

How does chlorine kill bacteria?

A

Chlorine reacts with water to produce HCl and HOCl. The HOCl (hypochlorous acid) kills bacteria.

73
Q

Uses of chlorine in pulp/paper industry and in plastics

A

Bleaches pulp/paper.

Used to make the monomer of the plastic PVC (polyvinylchloride).

74
Q

Percentage N in Earth’s atmosphere

A

79%

75
Q

Reactivity of N gas

A

Chemically unreactive, though lightening can cause a small amount of nitric oxide.

76
Q

What causes smog?

A

Nitric oxide combines with other atmospheric pollutants to produce photochemical smog.

77
Q

Ammonia

A

NH3. Strong-smelling gas at room temp. Soluble in water. Forms ammonia solution (basic). Neutralises to form ammonium salts.

78
Q

How is ammonia made in NZ?

A

Modified Haber Process. Natural gas is the source of hydrogen. Air is the source of nitrogen. A catalyst is used in some stages.

  1. Preparation of gas mixture of hydrogen and nitrogen.
  2. Remove of CO2 and CO.
  3. Formation using Haber Process.
79
Q

Uses of ammonia

A

Making nitric acid (for explosives). Agricultural chemical for soil. Synthetic fibre manufacture. Liquid for use as a refrigerant.

NCEA Level 1 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions