Question #b4ab9

1 Answer
Oct 23, 2017

Here's what I got.

Explanation:

For starters, calculate the charge of the ion by using the equation

#color(blue)(ul(color(black)("net charge" = "no. of protons " - " no. of electrons"#

In your case, you have

#"net charge" = 52 - 54 = -2#

This tells you that the ion carries a #2-# charge, which implies that you are dealing with a negatively charged ion, or anion.

Now, the isotope notation of this ion requires

  • the atomic number of the element, #Z#
  • the mass number of the isotope, #A#

http://chemkjj.blogspot.ro/2015/06/c1-12-proton-number-mass-number-ions.html

In your case, you know that the element has #52# protons, which means that

#Z = 52#

In order to find the mass number of the isotope, simply add the number of protons and the number of neutrons present in the nucleus.

#A = "52 protons + 76 neutrons"#

#A = "128 nucleuons"#

This means that the symbol of the neutral isotope will look like this

#""_(color(white)(1)52)^128"X"#

A quick look in the Periodic Table will reveal that you're dealing with tellurium-128, an isotope of tellurium, #"Te"#.

#""_(color(white)(1)52)^128"Te"#

Finally, to show that this is an anion and not a neutral atom, add the net charge.

#""_(color(white)(1)52)^128"Te"^(2-)#