Exam 2: The Chemical Context of Life

Carbon-12 is the most common isotope of carbon,and has an atomic mass of 12 daltons.A mole of carbon in naturally occurring coal,however,weighs slightly more than 12 grams.Why?

Knowing just the atomic mass of an element allows inferences about which of the following?

Which of the following best describes the relationship between the atoms described below?

Compared with ³¹P,the radioactive isotope ³²P has

The atomic number of nitrogen is 7.Nitrogen-15 is heavier than nitrogen-14 because the atomic nucleus of nitrogen-15 contains how many neutrons?

Which of the following correctly describes chemical equilibrium?

Electrons exist only at fixed levels of potential energy.However,if an atom absorbs sufficient energy,a possible result is that

Which of the following molecules contains the most polar covalent bond?

Use the following information to answer the questions below. You are investigating how chemical reactions occur.You place two reactants together and measure the concentration of product at regular intervals.After a time,the amount of product becomes stable. -If you add more product to the solution,you would expect to see

What results from an unequal sharing of electrons between atoms?

The organic molecules in living organisms have a measurably lower ratio of carbon-13/carbon-12,two stable isotopes of carbon that comprise approximately 1.1% and 98.9% of atmospheric carbon,respectively.What is a reasonable explanation for this phenomenon?

What is the difference between covalent bonds and ionic bonds?

The three types of subatomic particles pertinent to the study of biology are

A dalton is a unit of

Which of the following statements correctly describes any chemical reaction that has reached equilibrium?

The precise weight of a mole of some pure elements like silicon (Si)can vary slightly from the standard atomic mass,or even from sample to sample.Why?

What is the maximum number of electrons in a single 2 p orbital of an atom?

In the term trace element,the modifier trace means that