There should be mass balance and the charge balance between the reactants and the products
Mass balance : total no of individual atoms of each type should be balanced before and after the reaction
Charge balance : Overall charge of the reactants should be balanced with the overall charge of the products
You can balance,
1)by just looking at it
2)by Algebraic method given above or
3)by the redox method
You need to know how to get the oxidation numbers in order to use the oxidation method
There are two types of fermentation aerobic and anaerobic. Aerobic are those that need oxygen to ferment while anaerobic are those who do not need oxygen. Products of fermentation are usually water, ethanol, lactic acid and carbon dioxide. Other products are acetone and butyric acid.
7 becuse it splits in half
For a p type of semiconductor we need a dopant which is from 13th group in periodic table
Al , B, Ga, In Tl
So the correct element will be In : Indium
The other elements belongs to 15th group and hence will give n type semiconductor