While baking in the oven, moisture and water in the batter heats up as the cake bakes. The heat turns this moisture to steam. Steam expands and rises, trying to escape. The cake contains the steam inside it, so the cake rises and becomes airy.
the purpose of baking powder in a cake is to make it rise and not make it flat and if you put too much of baking powder your cake might burst in the oven/microwave what ever you use
to make it rise and be less dense
Baking powder is not a gas, but it does make a cake rise by releasing carbon dioxide into the batter through chemical reaction.
to make it 'rise', have air pockets, not be dense
It's not the milk alone that makes a cake rise. If the recipe includes milk it probably also contains either baking powder and/or baking soda. This combination of a base (Baking soda or Baking Powder) and an acid (milk) causes a slight chemical reaction which causes the cake to rise.
Vinegar
Baking powder is a leavening agent, which is what causes the cake to rise. Too little baking powder will cause the cake to be tough and compact, and won't rise as expected.
It either helps whatever you're baking rise or make whatever you're baking soft and fluffy.
No. The eggs don't make cakes rise. It is the baking powder in the cake flour.
Self raising flour makes the cake rise, but if you don't have any you can use plain flour and baking powder which has the same effect. 225g plain flour and 4 teaspoons baking powder, will transform it into self raising flour.
No, baking powder is what makes cakes rise.
It depends on the type of cake. If you are making a sponge cake where the mixing method involves whipping the eggs and sugar, and then folding in the flour and butter, then it will be fine. The whipping created bubbles which will rise in the oven - baking powder will give it additional rise, but it is not vital.