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.
Atoms must have equal  number of protons and electrons. To find  the number of neutrons you must find is  something called the mass number. Unfortunately,  the mass number isn't listed on the Table of  Elements. To find the mass number, all you need to  do is round the atomic weight to the nearest whole  number.he number of electrons in an element can change. For a neutral atom (net charge of zero), the number of protons is exactly equal to the number of electrons. So the number of electrons is also the same as the atomic number. However, it is possible to remove electrons and not change the identity of an element.