Which of the following pairs of elements is most likely to form an ionic bond?

A.

calcium and fluorine

B.

carbon and oxygen

C.

phosphorus and chlorine

D.

nitrogen and oxygen

Write an equation that shows the formation of the phosphide ion from a neutral phosphorus atom.

How many moles of iron can be made from 3 miles of Fe2O3

Potassium has a mass number of 40 and an atomic number of 19. how many protons does it have?

What effect does the addition of a catalyst have on a chemical reaction at equilibrium?

Why does gas have a low density?

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.