Calculate the number of moles corresponding to 2.007 x 1028 atoms of helium.

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

A2.5% (by mass) solution concentration signifies that there is a 2.5 % (by mass) solution concentration signifies that there is blank of solute in every 100 g of solution. of solute in every 100 g of solution