What is the average mass of an atom whose relative atomic mass is 39?

Can you reduce your impairment by drinking coffee or cold showers? true or false?

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution? a. 3.88 m, b. 1.03 m, c. 1.5 m, d. 15.5 m

What is the result of multiplying (2.5 × 1010) × (2.0 × 10-7)? a. 5.0 × 103 b. 5.0 × 10-3 c. 5.0 × 1017 d. 5.0 × 10-17