Chemistry Unit 2- Metals, metal ores and alloys

HideShow resource information
  • Created by: Bella B
  • Created on: 09-01-16 21:04
What are IONS?
Ions are electrically charged particles forms when atoms lose or gain electrons.
1 of 51
How do metal atoms become positively charged?
They LOSE the electron(s) in their highest energy level- this is because atoms have no overall electrical charge so when they lose the electron, they have lost the negative charge that made them neutral.
2 of 51
How do non-metal atoms become negatively charged?
They GAIN the electron(s) from another atom and become negatively charged- atoms have no overall charge so when they gain a negative electron they become negatively charged!
3 of 51
The strong ELECTROSTATIC forces of attraction between oppositely charged ions. (REMEMBER- opposites attract)
4 of 51
What atoms does ionic bonding occur between?
5 of 51
What is the resulting compound of Ionic Bonding called?
6 of 51
What are some reactions of ionic bonding?
sodium+chlorine-->sodium chloride. magnesium+oxygen--> magnesium oxide. calcium+chlorine--> calcium chloride
7 of 51
What happens in the reactions of Ionic Bonding?
The metal atoms give electrons to the non-metal atoms. The metal atoms become positive ions and the non-metal atoms become negative ions!
8 of 51
What can Dot and Cross diagrams be used to show?
They show the ions in ionic compounds- IONIC BONDING=D&C with brackets!!
9 of 51
What is a covalent bond?
It consists of a shared pair of electrons. A covalent bond can be represented by a straight line or D&C diagram.
10 of 51
What is covalent bonds between?
11 of 51
What can DOT and CROSS diagrams be used to show too?
Covalent Bonds!! These type of D&C diagrams have no brackets and the atoms are joined.
12 of 51
What are double covalent bonds?
Molecules can have a double covalent bonds- meaning they have two shared pairs of electrons
13 of 51
What are triple covalent bonds?
Three shared pairs of electrons.
14 of 51
How are double and triple covalent bonds shown?
A double covalent bond is shown by a double line (I I), and a triple covalent bond by a triple line (I I I)
15 of 51
What do METAL atoms form?
16 of 51
What do NON-METAL atoms form?
17 of 51
Why do ionic compounds have a high melting point?
Ionic bonds are VERY STRONG so a lot of eneryg is needed to break them. Ionic compounds contain many of these strong bonds so they need a lot of energy- HEAT- to break them.
18 of 51
Why can ionic compounds conduct electricity when they're dissolved in water or when they're melted?
Their ions are free to move and carry the current! They cannot conduct as a solid because their ions can't move around in their lattice structure.
19 of 51
These contain only a few atoms held together by strong COVALENT BONDS.
20 of 51
How do simple molecular substances melt or boil?
They have very strong bonds between the atoms but weaker forces holding the molecules together. When 1 of the substances melts or boils, it's these weak intermolecular forces that break!
21 of 51
What are the properties of simple molecular substances?
LOW MELTING & BOILING POINTS- because the weak intermolecular forces break down easily. NON-CONDUCTIVE- substances with a simple molecular structure don't conduct electricity- they don't have any free electrons/ an overall electric charge!
22 of 51
They have GIANT COVALENT STRUCTURES! They contain a lot of non-metal atoms each joined to adjacent atoms by COVALENT BONDS!
23 of 51
How are macromolecules arranged?
In GIANT LATTICES!! These are strong because of their many bonds involved.
24 of 51
Why do substances with giant covalent structures have very high melting points?
Because a lot of strong covalent bonds must be broken!
25 of 51
Diamonds and graphite!!
26 of 51
Why are DIAMONDS strong and hard?
Diamonds are a form of carbon where each carbon atom is joined to 4 OTHER CARBON ATOMS = giant covalent structure. As a result diamonds are very HARD and they have HIGH MELT. POINTS.
27 of 51
Do DIAMONDS conduct electricity?
NO!! This is due to the need to break very strong covalent bonds operating in 3-dimensions. doesn't conduct electricity. All the electrons are held tightly between the atoms, and aren't free to move
28 of 51
What are the properties of a DIAMOND?
Lustrous (shiny), Colourless and clear (transparent), Hard, High Melting Point, Insoluble in water (does not dissolve) and does not conduct electricity
29 of 51
Why are DIAMONDS useful and what are they used for?
Because they have many useful properties. They are used for JEWELLERY and HEAVY DUTY DRILL BITS!! Like those used to drill through rocks in the oil exploration industry
30 of 51
What is SILICA?
It's found in sand and has a similar structure to DIAMOND!
31 of 51
What are the properties of SILICA?
Hard, High Melting Point. It contains silicon and oxygen atoms instead of carbon atoms!!
32 of 51
It is formed of carbon where the carbon atoms form layers!
33 of 51
Why is graphite softer than diamond?
Graphite is made of layers of carbon atoms. Each carbon atom in a layer is joined to only 3 other C atoms. The layers can slide over each other because the forces
34 of 51
How does Graphite conduct electricity?
Graphite contains delocalised electrons (free electrons). These electrons can move through the graphite, carrying charge from place to place and allowing graphite to conduct electricity.
35 of 51
What are the properties of GRAPHITE?
Like diamond its properties include: Lustrous, High melting point, Insoluble in water. But unlike diamond its props are: black and opaque, slippery and its an electrical conductor.
36 of 51
What is an ALLOY?
An alloy is a mixture of two or more elements, where at least one element is a metal! Many alloys are mixtures of 2 or more metals.
37 of 51
How are alloys harder than pure metal?
Alloys contain atoms of different sizes. These different sizes distort the regular arrangements of atoms! This makes it harder for the layers to slide over each other.
38 of 51
What are some examples of alloys?
BRASS- used in electrical fittings, 70% copper+30% zinc. DURALUMIN- used in aircraft manufacturing- 96% aluminium+ 4% copper
39 of 51
They can return to their original shape after being bent or twisted.
40 of 51
What is NITNOL?
It's a shape memory alloy made from nickel and titanium. It's used in dental braces and spectacle frames!
41 of 51
Why are metals MALLEABLE?
Metals consist of layers of atoms- the layers can slide over one another when the metal is hammered, pressed or bent.
42 of 51
What does malleable mean?
That a substance is able to be bent and shaped.
43 of 51
It's the force of attraction between free electrons and metal ions!! They are strong, so metals can maintain a regular structure and usually have high melting/boiling points.
44 of 51
What happens when metals form giant structures?
Electrons in the outer shells of the metal atoms are free to move!!
45 of 51
Why are metals good conductors of electricity and heat?
There are free electrons that can move throughout the metal!
46 of 51
What do the properties of POLYMERS depend on?
The CHEMICALS they are made from and the CONDITIONS they are made in!
47 of 51
They soften when heated and can be shaped when hot. The shape will harden when it's cooled, but can be heated and reshaped when heated up again.
48 of 51
What makes Thermosoftening polymers flexible?
The tangled polymer chains can uncoil and slide past each other, making it a flexible material! This is because they have no cross links.
49 of 51
They have different properties to thermosoftening polymers. Once they are moulded they DON'T soften when heated and CANNOT be reshaped!
50 of 51
Why are Thermosetting Polymers not flexible?
Its polymer chains are joined together by cross-links, so they can't slide past each other easily.
51 of 51

Other cards in this set

Card 2


How do metal atoms become positively charged?


They LOSE the electron(s) in their highest energy level- this is because atoms have no overall electrical charge so when they lose the electron, they have lost the negative charge that made them neutral.

Card 3


How do non-metal atoms become negatively charged?


Preview of the front of card 3

Card 4




Preview of the front of card 4

Card 5


What atoms does ionic bonding occur between?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Metals, metal ores and alloys resources »