An atom has the following electron configuration. 1s22s22p 3s23p3
How many valence electrons does this atom have? (4 points)
3
5
8.
15

When hydrochloric acid reacts with potassium hydroxide solution, the following reaction occurs. hcl (aq) + koh (aq) h2o (l) + kcl (aq) the reaction gives off heat energy, so it is an reaction.

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.