How many eggs are in one mole of eggs?
A mole is a word that stands for a number. One mole means 6.02 X 10^23.
One mole of atoms, of course. This is equivalent to asking "How many eggs are in 1 dozen brown eggs?", the answer is one dozen. Both the mole and the dozen are unit less quantities that could (in principle) be applied to anything, however the mole is a much much larger quantity than the dozen (by 22 orders of magnitude). One could even talk about having a mole of eggs... but there wouldn't be enough…
The term "mole" is the same as the term "dozen", except that the mole represents a much greater number. Whereas "a dozen eggs" means 12 eggs, "1 mole of eggs" means 6.03x1023 eggs. The reason for using such a large number is that there are typically huge numbers of molecules involved in any chemical reaction in Chemistry.
6.022 x 1023 molecules are in a mole. 12 molecules are in a dozen. 6.022 x 1023 atoms are in a mole. 12 atoms are in a dozen. 6.022 x 1023 eggs are in a mole. 12 eggs are in a dozen. A mole is like a dozen. I hope the examples above explain the concept. You may message me if you need any further clarification.
That depends on the substance, and on whether you are considering atoms ore molecules. One mole has as many grams as the atomic or molecular mass of the substance. For example, one mole of atomic hydrogen has 1 gram; one mole of molecular hydrogen has 2 grams, one mole water has 18 grams, etc., since those numbers are the corresponding atomic or molecular masses.