Question

What does `"X"` represent in the following symbol: `""_35^80"X"` ?

Answer 1

Do you mean `35/80X`? That should be Bromine

Explanation:

X shows the name of the element in the periodic table

Answer 2

For `""_(35)^(80) X`, recall that the isotope notation uses the following symbols:

`bb(""_(Z)^(A) X^(pmn))`

• `Z` is the atomic number, which tells you the number of protons in the element and also its identity.
• `A` is the mass number, which tells you the number of protons plus the number of neutrons.
• `X` is the chemical symbol of the element, and it must correspond to the atomic number.
• `pmn` is the signed charge.

So, with an atomic number of `35`, we look at the fourth period and seventh group/column to get `"Br"`, or bromine. With a mass number of `80`, we have the `"Br"-80` isotope.