2. (2 points) Calculate the Effective Nuclear Charge for each atom. Show all of your work for full credit. Se: Br: (1 point) Which atom is larger? (This is your claim.)

Bromine.

Explanation:

There is more nuclear charge on bromine because in bromine, there are 35 number of protons and 46 number of neutrons while in selenium, there are 34 number of protons and 45 number of neutrons. The atomic size of selenium is larger because they have lower nuclear charge as compared to bromine and we know that when we go to the left of periodic table atomic size increases which attract the electrons towards itself so the shell comes close to the nucleus and decrease occurs in atomic radius.

it's all four options.