Moles

And today's question.

Why do we need ANOTHER unit?

What we already know

  • Atoms of an element are all the same (not quite true, later we will talk about this)

  • Atoms of different elements are different - hydrogen atoms are different to gold atoms - they have different masses

Water

hydrogen    +     oxygen    ----->    water

But atoms are small

really, really small, 

So how can we use it?

we say that 1 mole of an element is equal to the mass in grams of the atomic mass.

1 mole of Hydrogen

  • 1.008 grams of Hydrogen

  • 60200000000000000000000000 atoms

Video on the website

Document with practice

Year 8 - 4th December 2015 - Lesson 2 [Moles]

By Gavin King

Year 8 - 4th December 2015 - Lesson 2 [Moles]

introduction to moles

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