Muscles need a stimulus from which to of the following to "tell" them contract? A. A muscle call B. The skeleton C. A nerve cell D. None of the above

The N-H bond in ammonia is polar because A: nitrogen occupies more space than hydrogen. B: hydrogen is much more electronegative than nitrogen. C: it is a hydrogen bond. D: it is an ionic bond. E: nitrogen is much more electronegative than hydrogen.

A bead has a mass of 15 g. You place it in a graduated cylinder that has 20 mL of water. After placing the bead in, the water level is now 30 ml. What is the density of the bead?

Choose the correct name for the following compound: nacl. chlorium sodide sodium chloride

How many neutrons are in an atom of copper?

You dissolve 3 moles of NaCl into 12 L of water. What is the Molarity?

A student states the following: "Since acetone (nail polish remover) evaporate more readily than water, one would assume that acetone has weaker intermolecular forces than water." Evaluate their claim. (2 sentences)

A catalyst can only be used once. True False

On what basis do we distinguish between substances and separate them from one another?

What is the net ionic equation for the following reaction? H2CrO4 + Ba (OH) 2

How does improving food-storage facilities make farming more sustainable? A. It decreases the amount of water needed. B. It keeps food from rotting as quickly and being wasted. C. It decreases the amount of land needed. D.