Which of the following isotopes is most useful for dating plant and animal remains?

A. potassium - 40

B. Uranium - 238

C. Carbon-14

D. Lead-212

Why is desertification a problem?

What does the sum of the protons and neutrons in an atom equal

A geological sample is found to have a Pb-206/U-238 mass ratio of 0.337/1.00. Assuming there was no Pb-206 present when the sample was formed, how old is it? The half-life of U-238 is 4.5 * 109 years. 1.4 * 1010 years2.1 * 109 years7.3 * 1011 years7.

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

Neglecting friction, if a pendulum bob has 100 joules of kinetic energy at the bottom of its swing, how much potential energy does it have at the top of its swing? A) 0 J B) 50 J C) 100 J D) 200 J

A system that transmits genetic information from one generation to the next

Consider the following four solutions: a. NaCl in water b. Acetic acid in water c. Acetic acid in benzene d. Naphthalene in benzene Which of these solutions has the strongest solute-solvent interactions and the interaction is of which type?1.

Formula for sulfur tetrafluoride

Geologists think that parts of the Appalachian Mountains formed originally from sediments accumulating in shallow swamps. The weight of the sediments caused the area beneath them to sink, allowing more sediments to accumulate.

What volume would 1.5 mol of nitrogen gas occupy at standard temperature and pressure?