238U
17P 15
The symbol is Ba. The number of neutrons equal the number of protons.
a superscript designating the number of nucleons is placed before the chemical symbol. Nucleons are either protons or neutrons. Example: Carbon (C) has 6 protons and 6 neutrons. Carbon-14 has 2 extra neutrons, and is designated 14C
7
204/80 Hg^2+
The chemical symbol for fluorine isotope with 9 neutrons is 18F (18 is a superscript).
There are a variety of isotopes that have 30 neutrons. It isn't the number of neutrons that determines an element, but the number of protons. Electrons generally balance the number of protons.
17P 15
The symbol is Ba. The number of neutrons equal the number of protons.
231
This is a stable isotope of sulfur: 1616S.
a superscript designating the number of nucleons is placed before the chemical symbol. Nucleons are either protons or neutrons. Example: Carbon (C) has 6 protons and 6 neutrons. Carbon-14 has 2 extra neutrons, and is designated 14C
Nickel (Ni) is a chemical element with the chemical symbol Ni and atomic number 28. Nickel has: protons=28 neutrons=30 electrons=28 atomic mass=58 atomic #=28
7
204/80 Hg^2+
- The atomic symbol is only an abridged form of the name of a chemical element. - The chemical symbol of neon is Ne; the atomic number is 10. - The atomic number is equal to the number of protons and electrons. - Number of neutrons = Atomic mass of an isotope - Atomic number
You are looking for the symbol of cesium (Cs) and indication of its mass number. The mass number is the sum of the protons and neutrons. So if every atom of cesium has 55 protons, then the mass number of this isotope is 137. The mass number is indicated in superscript before the symbol: 137Cs