Set up the conversion factors to convert inches to centimeters and then from centimeters to millimeters. Can someone explain what I did wrong & how I am supposed to solve it correctly.

Express the following number in scientific notation. 0.026890 =

How many moles of oxygen react with 12 moles of aluminum

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