Chemistry paper 1

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Cards (443)

Atoms 
They are very small, about 77,400,000,000,000,000,000 of them could fit on the head of a pin
Atoms contain protons, neutrons and electrons
The nucleus
It is the central core of the atom
It contains protons and neutrons
It has a diameter of about 100,000 times smaller than the overall atom
Electrons
They are negatively charged particles that move around the nucleus
The number of protons equals the number of electrons in an atom
This is because they have the same charge
Atomic number 
The number of protons in the nucleus of an atom
Mass number 
The total number of protons and neutrons in the nucleus of an atom
Carbon-12
6 protons, 6 neutrons
Atoms may be combining and the things that hold them together are called chemical bonds
the reactivity series is the relative ability of metals to displace other metals from their compounds
a metal that can be displaced by another metal is less reactive than the one that does the displacing
metal oxides are basic as they neutralise acids, forming salts and water
Periodic Table 
A table that organises the chemical elements
The Periodic Table has 17 elements
acidic oxide + base = salt + water
neutralisation reaction - an acid and alkali combine to form a salt and water
A reaction between two elements or compounds where they form a new compound is known as a combination reaction.
basic oxide + acid = salt + water
When a substance burns it undergoes a rapid exothermic oxidation reaction with oxygen in air.
In a combustion reaction, oxygen gas reacts with a fuel (such as hydrocarbons) to produce carbon dioxide and water vapour.
alkali metals react with cold water to form hydrogen gas and an alkaline solution (hydroxide)
Elements
Consist of Atoms With the Same Atomic Number
Atoms can have different numbers of protons and neutrons
Atoms
Can be Represented by Symbols
Isotopes 
Are the Same Except for Extra Neutrons
Have the same atomic number but different numbers of neutrons