Which of the following statements about moles is correct?

A mole of Cu atoms has the same number of atoms as a mole of He atoms.

A mole is 6.02 x 1024

There are more atoms in a mole of carbon than in a mole of helium.

A mole is 6.2 x 1022

The first step is in oil is what

Which of these particles has the greatest mass? (1) alpha (3) neutron (2) beta (4) positron

Muriatic acid is an old name for hydrochloric acid. The commercial grade (impure) solution is still sold as muriatic acid. You use it in toilet bowl cleaners, for cleaning masonry, and for adjusting the pH of swimming pools.

What's the Charles and Boyle's law?

Would an atom containing 8 protons, 9 neutrons, and 8 electrons be considered charge-neutral

A pycnometer weighs 25.60 g empty and 35.55 g when filled with water at 20°C. The density of water at 20°C is 0.9982 g/ml. When 10.20 g lead is placed in the pycnometer and the pycnometer is again filled with water at 20°C, the total mass is 44.83 g.

How does weathering affect the surface area of a rock? Explain your answer.

How would each of the following procedural errors affect the results to be expected in this experiment? Give your reasoning in each case. (A) Not all of the liquid was vaporized when the flask was removed from the water bath.

What volume of 2.00 m must be added to 150.0 ml of 1.00 m chloroacetic acid to produce a buffer solution having a ph of 3.30?

What is the mass (g) of 500. ml water if the density is 0.9901 g/ml?