Year 10 Chemistry Topics

Basis of Atom

• Electrons

• Protons

• Neutrons

• Outer shells

Atomic Structure

For example: Carbon

The atomic number for carbon is 6

The mass number for carbon is 12

Now to calculate — protons: 6 electrons: 6 neutrons: 6

12-6

(this is lithium not carbon)

Outer Shells

• 1st shell holds 2

• 2nd shell holds 8

• 3rd shell holds 8

— Now let’s use Carbon as an example again

Carbon has 6 electrons,

• First shell takes 2 —> now 4 left

• Second shell takes up to 8, but only 4 are left —> so it gets 4.

So therefore, Carbon’s electron arrangement is: 2,4.

Displacement

• A more reactive metal will displace the less reactive metal from a compound

—> more reactive + less reactive compound

—> reaction happens

—> less reactive + more reactive compound

—> nothing happens, the less reactive metal will not displace the more reactive metal.

Example:

Zinc + copper sulfate

Zinc will displace Copper because Zinc is far more reactive than Copper.

—> Zinc sulphate + copper

(or write it as ZnSO₄ + Cu if you’re feeling cute)

However, if you try Copper + zinc sulphate,

Copper is less reactive than zinc, so therefore..

Nothing happens!