Chemistry 1 Flashcards
What are atoms made up of?
1) Protons
2) Electrons
3) Neutrons
What is the mass and relative electrical charges of the sub-atomic particles?
Sub-atomic: charge: mass
Protons : +1 : 1
Electrons : -1 : tiny
Neutrons : 0 : 1
What are elements in Group 0?
Noble Gases - they are unreactive as their atoms have a stable outer shell.
What are the similarities of the elements in the same group?
They have the same number of electrons in their outer shell; this gives them similar chemical properties.
What is Limestone and what can it be used for?
It is mainly the compound calcium carbonate - CaCO3
Limestone is quarried out of the ground and it can be used for building materials .
What is the ‘limestone reaction cycle’?
When calcium carbonate is heated it thermally decomposes it makes calcium oxide and carbon dioxide.
Then you add drops of water to the calcium oxide to get calcium hydroxide. (This is an alkali which can be used in neutralisation reactions)
Calcium hydroxide in water (limewater) reacts with carbon dioxide to get calcium carbonate.
What four other metals have a similar heating properties to Calcium Carbonate?
Magnesium, Zinc, Copper and Sodium all decompose on heat in similar ways.
What happens when a carbonate reacts with acid?
Is limestone affected by this?
It produces carbon dioxide, a salt and water.
Limestone is damaged by acid rain.
What is one way we can test for carbon dioxide?
Limewater - the carbon dioxide turns the limewater cloudy.
What is the process of making cement?
Limestone and clay heated.
Cement is mixed with sand to make mortar.
What is a metal ore?
Is it always economic to extract ores?
A rock that contains enough metal to make it worthwhile extracting the metal from it.
In many cases the ore is an oxide of the metal.
No, it changes over time.
For example; If the market price of a metal drops, it might not be worth extracting it.
Are metals found as compounds?
Most of them are found in compounds and need chemical reaction to extract the metal.
However there are some unreactive metals, such as gold, which are found in the earth as the metal itself.
How is a metal extracted if its less reactive than carbon?
Example?
Metal extracted from its oxides by reduction with carbon.
Iron oxide is reduced in a blast furnace to make iron.
How is a metal extracted if it’s more reactive than carbon?
What is a down side to extraction?
Extracted by electrolysis of molten compounds.
They require large amounts of energy making them expensive.
How can copper be extracted? - copper-rich ores
Heating the ores in a furnace - which is called smelting.
The copper can be purified by electrolysis however the supply for copper-rich ores is limited.
