Chemistry 1A Flashcards
(30 cards)
What are the properties of the nucleus of an atom?
The nucleus is in the middle of an atom and contains protons and neutrons.
What kind of charge do protons have?
Protons are positively charged
What kind of charge do neutrons have?
Neutrons have no charge (they are neutral)
How many electrons are in an atom?
The number of protons always equals the number of electrons in an atom.
Do atoms have an overall charge?
Atoms have no charge overall (they are neutral)
What happens to an atom when some electrons are added or removed?
The atom becomes charged and is then an ion
What is an element?
A substance that only contains one type of atom
How many electrons can fit in each electron shell?
1st shell: 2
2nd shell: 8
3rd shell: 8
How is a compound made?
When different elements react, atoms form chemical bonds with other atoms to form compounds.
What is ionic bonding?
When a compound which is formed from a metal and a non-metal consists of ions. The metal atoms lose electrons to form positive ions and the non-metal atoms gain electrons to form negative ions. The opposite charges of the ions mean they are strongly attracted to each other.
What is a convalent bond?
Where each atom shares an electron with another atom, each atom has to make enough convalent bonds to fill its outer shell.
What do balanced symbol equations show?
They show the atoms at the start and the atoms at the end and how they’re arranged. For example;
magnesium + oxygen —> magnesium oxide
2Mg + O2 —> 2MgO
There should always be the same number of atoms of each element on both sides of a balanced equation.
True or False?
True
There has to me the same number of atoms on both sides- they can’t just disappear.
How do you balance an equation?
By putting numbers in front of the formulas where needed.
What is limestone mostly made of?
Calcium Carbonate (CaCO3)
What happens when limestone is heated?
It thermally decomposes to make calcium oxide and carbon dioxide
What is a metal ore?
A rock with enough metal to make it worth extracting
How can metals be extracted from their ores?
A metal can be extracted from its ore chemically- by reduction or using electricity to split the metal from its ore- electrolysis
What is electrolysis?
The breaking down of a substance using electricity
What are the disadvantages of limestone quarrying?
- Ruins landscapes
- Noise pollution
- Destroys animal habitats
What are the advantages of limestone quarrying?
- Produces the limestone people want
- Provides jobs
- Landscaping can be done to replace quarry
Why is recycling metals important?
- Fossil fuels are running out so we need to conserve them
- Burning fossil fuels contributes to acid rain
- Recycling uses less energy
- Recycling is cheaper
- Cuts down on the amount of rubbish at landfills
What are the main properties that most metals have?
- Metals are strong
- They are good conductors of heat
- They conduct electricity well
What is an alloy?
A mixture of two or more metals
