Which of the following is the Sl unit used by chemists to measure the amount of an element or substance?

A. molecule

B. mole

C. atom

D. milliliter

If atmospheric pressure on a certain day is 749 mmhg, what is the partial pressure of nitrogen, given that nitrogen is about 78% of the atmosphere?

Problem 12.78 Determine the mass of the earth knowing that the mean radius of the moon's orbit about the earth is 238,910 mi and that the moon requires 27.32 days to complete one full revolution about the earth.

How long does it take for tylenol to work?

What type of radiation is identical in mass charge to a helium nucleus?

What provides the source of the earth's magnetic field? the north and south poles of the earth. the sun. the ocean's electric currents. the core of the earth.

Which type of reaction will for a chemical bonded combination

What kind of change is salt dissolving in water

Which of these is the most effective way for manny to cool down after kickboxing? start static stretches to increase his flexibility walk around to lower his heart rate sit and catch his breath to avoid light-headedness run one to three miles to

One of the driving forces of plate motion is: A. volcanic eruptions along coastlines B. meteor impacts in the ocean basins C. convection currents in the mantle D. hot liquid magma in the inner core

Which element is required for the combustion of fossil fuels? nitrogen hydrogen oxygen carbon