87x+2 , the difference between electrons and neutronsnumber is 13. What is the atomic number of x?

The atomic number of an element is equal to the number of protons in its nucleus. The number of protons is also equal to the number of electrons in a neutral atom.

Given that the difference between the number of electrons and neutrons is 13, we can set up the following equation:

Number of electrons - Number of neutrons = 13

We also know that the number of electrons is equal to the atomic number, which is represented by 'x' in the equation 87x + 2.

Therefore, we can substitute 'x' for the number of electrons in our equation:

x - Number of neutrons = 13

We can rearrange this equation to find the number of neutrons:

Number of neutrons = x - 13

Substituting this back into the equation 87x + 2, we get:

87x + 2 = 87(x - 13) + 2

Solving for 'x', we get:

x = 15

Therefore, the atomic number of the element is 15.