Gravity, the force of attraction between two masses, is an example of a ...

educated guess

hypothesis

theory

universal law

When an atom gains an electron it becomes a ___ ion

What are examples of fossil fuels?

Which is easier to observe, physical or chemical properties? why?

Calculate the standard reaction free energy of the following chemical reaction: 2Al (s) + Fe2O3 (s) → Al2O3 (s) + 2Fe (s)

What do the following have in common? Ne-20, f-1, Mg+2 A) They are isomers of each other. B) They all have the same number of electrons. C) They are different elements so they have nothing in common.

Which of the follwing is a pure substance: sugar, salt, water, or pepper? Explain how you know.

A chemistry student needs of isopropenylbenzene for an experiment. She has available of a w/w solution of isopropenylbenzene in carbon tetrachloride. Calculate the mass of solution the student should use.

Can an organism carry out cellular respiration without photosynthesis?

Predict the product for PtCl4 + F2

Calculate the formula mass of ethanol, c2h5oh. express your answer to three significant figures and include the appropriate units.