In the periodic table what does the number above the element tell you?

Answer 1

A superscript number to the left of an atomic symbol represents the mass number of a particular isotope of the element represented by the symbol. Sometimes this mass number appears on the right side instead of the left, but preferably a right superscript should be used only to indicate a net electrical charge.

Answer 2

Depends.

In a compound, if the number is AFTER the Element, eg H2O (with the 2 being subscripted) then the 2 refers to the number of that element in the molecule. In H2O this means 2 Hydrogen atoms and 1 Oxygen in the Water molecule.

If the number is BEFORE, and you are referring to ISOTOPES, then standard notation is to indicate the number of nucleons with a superscript at the upper left of the chemical symbol and to indicate the atomic number with a subscript at the lower left. Eg Carbon-12 would be 12 at the top-left before the "C" and 6 at the BOTTOM-left before the "C", indicating 12 neutrons+protons and 6 protons.

Answer 3

In the Periodic Table of elements, the atomic number is placed over the element's symbol. The atomic number tells you how many protons are in an atom of that particular element. The number that is placed above and to the right of an element symbol means the Atomic Mass of a particular isotope. For example, U238 is a uranium isotope that has an atomic mass of 238. Atomic mass is not the same as atomic number. The mass depends upon both protons and neutrons.

Answer 4

The number above the element tells you the atomic number

Answer 5

The number(s) above the element symbol means the isotopes, basically the different versions of the elements, that are stable. They do not list the isotopes that are not stable.

Answer 6

The subscript represents the number of atoms of that element in the molecule.

Answer 7

The average atomic mass

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Answer 8

The mass number

Answer 9

This number is the atomic number.