Which term describes the sum of the number of protons and neutrons in an

atom?

A nuclear charge

B mass number

C atomic charge

D atomic number

Explain which of the following are correct statements of the Second Law of Thermodynamics and which are not. a. All reversible heat engines have the same efficiency. b. An engine connected to one heat reservoir can do work on the surroundings. c.

Explain the difference between the bohr model and the electron cloud model

Classify these molecules as polar or nonpolar.

If there are only a few remaining members of an insect species living in one area, which would most likely cause this species to become extinct? the introduction of new predators to the insects' environment

A certain hydrocarbon was found to contain only 18g of carbon and 4g of hydrogen in a 22g sample. Determine its Empirical formula

When an aqueous solution of silver nitrate is mixed with an aqueous solution of potassium chloride which are the spectator ions?

Investigating changes in colligative properties involves the measurement of a solution's concentration in molality instead of molarity because

Consider the following representation of a reaction mechanism. Step 1: Unimolecular (fast) Step 2: Bimolecular (slow) Step 3: Unimolecular (fast) Which conclusion about the rate law for the reaction above is reasonable? A.

1. Which of the following best describes an example of pure chemistry? a) testing the effects of lower concentrations of a drug on humans b) studying chemicals containing carbon c) developing a cure for osteoporosis d) finding an antidote for a new

Problem 1: For which of the following activities might you want to hire a chemist? A. building a garage B. testing a sample of water from a well C. finding a comet D.