Total 8,232. Note: In addition to its drugstores, Walgreens also operates home care facilities and specialty, institutional and mail service pharmacies. Its Take Care Health Systems subsidiary manages more than 400 convenient care clinics at Walgreens drugstores.
These different versions of hydrogen are called isotopes. All isotopes of a particular element have the same number of protons, but have a different number of neutrons. If you change the number of neutrons an atom has, you make an isotope of that element.Currently, scientists know of 118 different elements.Some, like gold, silver, copper and carbon, have been known for thousands of years.f you change the number of neutrons an atom has, you make an isotope of that element. Currently, scientists know of 118 different elements. Some, like gold, silver, copper and carbon, have been known for thousands of years.
Atoms of the same element that differ in their atomic weight are called isotopes. Atomic weights are expressed in terms of a standard atom: the isotope of carbon that has 6 protons and 6 neutrons in its nucleus. This atom is designated carbon-12 or 12C.s long as the atom had 6 protons, it is an atom of carbon irrespective of the number of neutrons. Thus while 6 protons and 8 neutrons produce an isotope of carbon, 14 C, 7 protons and 7 neutrons produce a totally-different element, nitrogen-14.