1.) how many periods are on the periodic table? are periods the columns or the rows on the periodic table?

Which solution is an example of a nonelectrolyte? a. iodine in hexane b. sodium nitrate in waterc. acetic acid in waterd. hydrogen chloride in water

1) this is the structure in the cell nucleus that houses a cell's genetic information

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have