Four people are needed to lift a tv set with a single fixed pulley. how many people will be needed to lift the same tv set with a 2 fixed, 2 moveable pulley system? (ignore friction.)

Determine the empirical formula of a compound containing 40.6 grams of carbon, 5.1 grams of hydrogen, and 54.2 grams of oxygen. in an experiment, the molar mass of the compound was determined to be 118.084 g/mol. what is the molecular formula of the compound? for both questions, show your work or explain how you determined the formulas by giving specific values used in calculations.

Compare and contrast physical changes with chemical changes.

In the following redox reaction which is the oxidizing agent and which is the reducing agent? alcl3 + na nacl + al oxidizing agent = reducing agent =