Please help asap! Find the percent composition of all the elements in the following compounds

K2Cr2O7: % K % Cr % O

Which of these best describes the scientific process

Which formula can be used to calculate the molar mass of ammonia (nh3)? molar mass of n + molar mass of h 3 × molar mass of n + molar mass of h molar mass of n + 3 × molar mass of h 3 × molar mass of n + 3 × molar mass of h

How many miles of water are produced if 5.43 mol pbo2 are consumed