Although all atoms of an element have the same number of protons, individual atoms may have different numbers of neutrons. These differing atoms are called isotopes. All atoms of chlorine Cl have 17 protons, but there are chlorine isotopes with 15 to 23 neutrons. Only two chlorine isotopes exist in significant amounts in nature: those with 18 neutrons To write the symbol for an isotope, place the atomic number as a subscript and the mass number protons plus neutrons as a superscript to the left of the atomic symbol.
(PDF) Harris Quantitative Chemical Analysis 8th edition | David Garcia - bone-fishing.info
Your answers will appear exactly as you as you type them i. However, assignments in your course may require this type of keyboard-based "shorthand" for Mastering to correctly interpret your answers. You must complete these kinds of questions on a computer, not on a mobile device. If your answer box provides a chemical toolbar above the answer area: See alternate instructions. Atomic number presuperscript and mass number presubscript.
This worked problem demonstrates how to write nuclear symbols for isotopes of a given element. The nuclear symbol of an isotope indicates the number of protons and neutrons in an atom of the element. It does not indicate the number of electrons. The number of neutrons is not stated.
This worked problem demonstrates how to determine the number of protons and neutrons are in the nucleus of an isotope. One of the harmful species from nuclear fallout is the radioactive isotope of strontium, 90 38 Sr assume the super and subscripts line up. How many protons and neutrons are there in the nucleus of strontium?