Which of the following contains the smallest amount of matter

A sample of helium has a volume of 3 liters when the pressure is 500 kPa. What volume does the gas occupy at 300 kPa?

Write a nuclear equation to represent radium-226 decaying to radon-222 plus an alpha particle.

What is a chemical entity that forms a complex ion around a central atom?

According to table f which ions combine with chlorine ions to form an insoluble compound 1 - Fe2+ions. 2 - Ca2+ions 3 - Li+ions. 4-Ag+ions

Which transition occurs when light with a wavelength of 656 no is emitted by a hydrogen atom

What mass of potassium chlorate would contain 40grams of oxygen?

Identical forces act for the same length of time on two different masses. The change in momentum of the smaller mass is A) smaller than the change in momentum of the larger mass, but not zero. B) zero.

How many nuclei of 238 92 U 92 238 U remain in a rock if the activity registers 290 decays per second? (Note that the half life of Uranium-238 is 4.468x109 years)

A base can neutralize an acid. true or false

Hydrochloric acid (12.0 ml of 0.233 m) is added to 296.0 ml of 0.0579 m ba (oh) 2 solution. what is the concentration of the excess h + or oh - ions left in this solution?