An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.
20
the answer is 25

Chromium(iii) sulfate is a transition metal compound containing the metal chromium and the polyatomic ion sulfate. the oxidation state of chromium in this compound is , and the chemical formula of the compound is ( ) . reset next

What volume does 1.70 ×10–3 mol of chlorine gas occupy if its temperature is 20.2 °c and its pressure is 795 mm hg?

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.