Compounds Flashcards
(60 cards)
According to what are there rules for writing chemical formulae?
International Union of Pure and Applied Chemistry (IUPAC)
Why do compounds need names and formula?
- Can be overdosed
2. Clarity of which elements are present
Define chemical formula
Symbolic representation of a compound
What information does formulas give us?
- Name of compound
- Elements present
- Ratio of elements combined
Why should we understand how elements combine?
How they form compounds and how they affect things
When writing chemical formulae what do we use?
Valency - positive + negative
What do all halogens end with?
‘ide’
What do we use when writing formulae for non-transition metals?
Valency
When writing symbols of the elements for formulae. What goes first?
Metal goes first
What happens when there are two non-metals? formulae
Put the element furtherest to the left first (groups)
What happens when valency are the same?
They cancel = simplify
When writing formulae do the integer signs matter?
No. Used to indicate if receiving or giving ions. Formulae is positive
If a subscript is 1, what should happen?
Leave the 1 out
Define compounds
Consists of two or more different elements chemically bonded together in a fixed proportion
Which elements have more than one valency?
Transition metals
What is the formulae for transition metals written in?
Roman numerals
What happens when there is not stock notation?
Elements will have the valency of two
Why is silver an exception?
If no stock notation the valency will be one
I
1
II
2
III
3
IV
4 - iv drip
V
5 - vyf
VI
6
