Chemistry revision Flashcards
1
Q
Definition of atomic number
A
The number of protons in an atom.
2
Q
Definition of Mass number
A
The number of protons and neutrons in an atom.
3
Q
Definition of Isotopes
A
Atoms of the same element (same number of protons) but with a different number of neutrons.
4
Q
Definition of relative atomic mass (Ar)
A
The average mass of an atom compared to 1/12th the mass of carbon-12.
5
Q
Definition of atom
A
An atom is the smallest part of an element.
6
Q
Definition of molecule
A
A molecule is made of a fixed number of atoms covalently bonded together.
7
Q
How to calculate the Empirical formula
A
- find the mass of each element
- find the Ram of each element
- find the moles of each element
- find the ratio of moles for each element
- write down the empirical formula
8
Q
How to calculate the Molecular formula
A
- Find the Mr of the compound
- Find the Mr of the empirical formula
- Number of empirical formula units
- empirical formula X empirical formula units
- Write down the Molecular formula
