Science C5

HideShow resource information
What does the earths atmosphere contain?
Many gases
1 of 23
Name three of the gases that are in the air?
Oxygen (O2), Nitrogen (N2) and Argon (Ar)
2 of 23
Give the percentage of each gas in the air
78% Nitrogen, 21% Oxygen, 1% Argon and 0.04% Carbon Dioxide
3 of 23
What are most of the gases in the atmosphere?
Molecular substances
4 of 23
Explain why most molecular substances are gases
They have low melting and boiling points, as only little energy is needed to overcome the weak forces between the molecules.
5 of 23
What is covalent bonding?
This is when atoms share electrons with other atoms to create covalent bonding. Both atoms will have a full outer shell. The atoms bond due to the electrostatic attraction between the positive nuclei and the negative electronic shares between them.
6 of 23
What is the earths hydrosphere?
The earths hydrosphere consists of all the waters in the: oceans, seas, lakes, rivers and puddles. It also contains any compounds that are dissolved in the water.
7 of 23
What makes sea water 'salty'?
The compounds that dissolve in the water are ionic compounds called Salts. This is why sea water is salty.
8 of 23
What are ionic compounds made out of?
Charged particles called ions
9 of 23
Why do solid ionic compounds form crystals?
There are strong attraction forces between opposite charged ions, so a massive giant lattice of ions builds up. Strong chemical,bonds called ionic bonds are between all the ions. A single crystal of salt is one giant ionic lattice.
10 of 23
Do solid ionic compounds have high or low boiling points? Explain your answer
Ionic compounds have high boiling points. This is because the forces of attraction between the ions are very strong. It takes a lot of energy to overcome these forces and melt the compound, even more energy to boil it. Solid at room temperature.
11 of 23
Why can ionic compounds conduct electricity when dissolved in water, but not when they're solid?
When an ionic compound dissolves, the ions separate and are free to move in the solution. They carry an electric current so conduct electricity. When an ionic compound is solid, ions aren't free to move so can't conduct electricity.
12 of 23
What is the test for Carbon Dioxide?
Limewater
13 of 23
What is the Earths lithosphere?
It's the earths rigid outer layer, the crust and part of the mantle below it. It's made up of a mixture of minerals, often containing silicon, oxygen and aluminium.
14 of 23
What is the test for sulfates?
HCL and barium chloride
15 of 23
Name three abundant elements in the earths lithosphere
Silicon, limestone and sandstone
16 of 23
Give two reasons why it is good to recycle metals
Recycling saves money, and also cuts down on the amount of rubbish that get sents to landfills.
17 of 23
What is an ore?
An ore is an oxide of a metal.
18 of 23
What do the terms reduced and oxidised mean?
When a metal oxide loses its oxygen it is reduced. When oxygen is gained it is called oxidised.
19 of 23
What is electrolysis?
The decomposition of a substance using electricity. It needs a liquid to conduct the electricity, called the electrolyte.
20 of 23
Why do metals have high melting and boiling points?
They are used in everyday life, so therefore it wouldn't be much use if it was melting easily. Bridges are metal and shouldn't melt in hot weather, saucepans shouldn't melt when you are cooking.
21 of 23
Why are metals able to conduct electricity?
The 'free electrons' that are in all metallic bonds carry both heat and electrical current through the material. They are therefore good conductors of heat and electricity.
22 of 23
Why can molten ionic crystals act as electrolysis?
They also have free ions dissolved in water. They can therefore also conduct electricity.
23 of 23

Other cards in this set

Card 2

Front

Name three of the gases that are in the air?

Back

Oxygen (O2), Nitrogen (N2) and Argon (Ar)

Card 3

Front

Give the percentage of each gas in the air

Back

Preview of the front of card 3

Card 4

Front

What are most of the gases in the atmosphere?

Back

Preview of the front of card 4

Card 5

Front

Explain why most molecular substances are gases

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »