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

Aug 27, 2016

Do you mean $\frac{35}{80} X$? That should be Bromine

#### Explanation:

X shows the name of the element in the periodic table

Sep 4, 2016

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.
• $\pm n$ is the signed charge.

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