What do an orgasm, a multiplication problem and a photo of a dead body have in common? Each induces a slight, irrepressible expansion of the pupils in our eyes, giving careful observers a subtle but meaningful signal that thoughts and feelings are afoot. For more than a century, scientists have known that our pupils respond to more than changes in light.
Review. 1  Atoms have their electrons arranged in layers called shells. 2  In order to maintain electrical balance the number of electrons is equal to the number of protons in most elements.
Gold. Because each element has a unique atomic structure, no other element has exactly the same number of protons, neutrons and electrons. Gold's atomic number is 79, which corresponds to the number of protons in the nucleus of an atom of gold. There are 117 neutrons in the nucleus.Gold's 79 electrons exist at six different energy levels.old's atomic number is 79, which corresponds to the number of protons in the nucleus of an atom of gold. There are 117 neutrons in the nucleus. Gold's 79 electrons exist at six different energy levels.