Which of the following is an action-at-a-distance force? friction tension gravity air resistance

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.

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst

Which of the following is not one of the steps in the scientific method a. hypothesize b. summarize c. analyze d. familiarize