How could you increase the power of a wave in a spring

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Write the balanced equation for a reaction between aqueous nitric acid (hno3) and solid lithium metal (this is a single replacement reaction)

Which of the following units is not an official si unit? mole liter kilogram ampere