I need help with all of them

One nanometer is equal to how many meters?

Use the measurements in the table to determine which unidentified metal has the highest density. metal volume mass a 10.5 cm3 122 g b 14.2 cm3 132 g c 16.1 cm3 115 g d 12.7 cm3 126 g

What happens to the concentration of hydronium ions as the ph of a solution increases? a. hydronium ion concentration stays the same b. hydronium ion concentration decreases c. hydronium ion concentration increases