#"Atom W has 9 protons and 9 neutrons, Atom X has 8 protons and 9"# #"neutrons. Atom Y has 9 protons, and 9 neutrons. Atom Z has 10 protons"# #"and 10 neutrons."# What are the isotopes?

1 Answer
anor277
Mar 14, 2017

The number of nuclear protons gives #Z#, the atomic number......

Explanation:

And #Z# defines the identity of the element: #Z=1,H;Z=2,He;..........Z=6,C;........Z=37, Ru...........#

You don't have to remember these numbers, because a Periodic Table will be supplied to you in every test of chemistry and physics. You do have to be able to USE the Table.

Nuclear protons are conceived to have a positive charge. For a NEUTRAL element, there thus must be an equal number of negative charges, and these are supplied by #"electrons"#, which have negligible mass, unlike the proton, and are conceived to whizz about the nuclear core.

Also contained in the nuclear core, are various numbers of neutrons. Because a particular element may have various numbers of neutrons, this gives rise to the existence of #"isotopes"#, which are the same element, but isotopes have slightly different mass.

And so we identify the given nuclides, armed with a Periodic Table. All I do is look up the number #Z#, given by the number of protons:

#"Atom W"# #=# #"9 protons and 9 neutrons"#, #""^18F#

#"Atom X"# #=# #"8 protons and 9 neutrons"#, #""^17O#

#"Atom Y"# #=# #"9 protons and 9 neutrons"#, #""^18F#

(i.e. #W# and #Y# are the same isotopes)

#"Atom Z"# #=# #"9 protons and 10 neutrons"#, #""^19F#

#Z# and #Y# are different isotopes of the fluorine element. #W# and #Y# are the SAME isotope.

Please don't be blinded by science, and a few unfamiliar terms. The concept is fairly simple, and if you persist you will master it. A final question. We have #Z=92# for an unknown element. It has #146# neutrons in its nucleus. Can you identify the element, and the relevant isotope?

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