What are the 2 basic parts of an atom?

Mitosis is a type of cell division that produces cells that are identical to the parent cell. meiosis is a different type of cell division that produces cells that carry have a genetic material of the parent cell. based on the information provided how do the purpose of mitosis and meiosis differ

May someone me with these science questions

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?