Question

How many electrons are in a CL-34 ion with a negative one charge?

Answer 1

how many electrons does an neutral Cl atom have?

Answer 2

17

Answer 3

and what is the charge on an electron?

Answer 4

-

Answer 5

-1 right?

so if have a Cl ion with a -1 charge, how many electrons would have?

Answer 6

16?

Answer 7

nope, if it had 16 it would have lost one and it would have a 1+ charge.

when you add electrons to an atom it gains negative charges.

Answer 8

so 18?

Answer 9

yep

Answer 10

what does the 34 have to do with anything?

Answer 11

that's the mass number, the sum of protons and neutrons of the chlorine atom/ion.

do you know what isotopes are?

Answer 12

no.

Answer 13

they're atoms of the same element (that is the same number of protons, because it dictates the type of atom it is) but with a different number of neutrons.

So Cl-37 and Cl-38 will have the same number of protons (17) but will differ in the number of neutrons they have and thus the mass number.