Answer:
electron (-) and proton (+)
About the amount in a 20 oz gatorade bottle
The metalloid that has three valence electrons is Boron~
Option 2, Br. I'll go over why all other three options are incorrect.
Option 1 - Krypton is a Noble gas, and so it doesn't need to accept electrons since it has an octet.
Option 3 and 4 - Both Calcium and Barium are alkaline earth metals, and give away electrons, since they only have 2.
-T.B.