Space
One googol of atoms would be 10100 atoms or 1.66 × 1076 moles.
When hydrogen atoms fuse into helium atoms, a small amount of mass from the hydrogen is converted into a large amount of energy in accordance with Einstein's equation E=mc^2. This energy release results from the difference in mass between the initial hydrogen atoms and the resulting helium atoms.
Hydrogen atoms fuse to become helium atoms during the process of nuclear fusion in stars. This process releases a large amount of energy and is the source of the sun's energy.
The process in which large atoms are broken apart is called nuclear fission. This occurs when the nucleus of an atom splits into two or lighter nuclei, releasing a large amount of energy. Nuclear fission is used in nuclear power plants and nuclear weapons.
A very large, specific number of items
A large amount of energy. This naturally occurring reaction happens inside all stars and is called fusion.
The activation energy barrier. Combining H atoms and O atoms into water releases a large amount of energy, but breaking up H2 molecules and O2 molecules into H and O atoms requires a large (but not as large) amount of energy. You need to supply sufficient energy to get things started, after which it's generally self-sustaining (and very rapidly so; a stoichiometric mixture of H2 and O2 is quite explosive once ignited).
Produce a large amount of heat and energy which is utilized for many purposes
large amount
all atoms are generally the same size, so "large atoms" would mean molecules.
When a large unstable atom splits into two or more smaller atoms, it is called nuclear fission. This process releases a large amount of energy and can result in a chain reaction if not properly controlled.
Nuclear energy is produced by splitting the nuclei of atoms in a process called nuclear fission. This process releases a large amount of energy in the form of heat, which can be harnessed to generate electricity.