What is the mass of 18.8 moles of helium (He) atoms?

0.213 g

4.70 g

37.6 g

75.2 g

Is hot water added to a bath conduction, convection, or radiation

Suppose an empty plastic bottle is sealed tightly at room temperature and then placed in the freezer. After some time the bottle changes shape. The bottle becomes slightly crushed as the volume of the air in it decreases.

Which of the following best describes a person doing science? A. Dominick uses a computer to do his math homework. B. Lindsay measures the sizes of the craters on the Moon. C. Isabel invents a new kind of doorknob. D.

A solution is prepared by mixing 25.0 g H2O and 25.0 g C2H5OH. Determine the mole fractions of each substance.

According to Ohm's law, which combination of units is the same as the unit for resistance?

If you start with 100 grams of a radionuclide, how much will you have after two half-lives have passed?

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?