The ion 16O2 has A 8 protons 8 neutrons 8 electrons B 8 protons 8

The standard enthalpy of vaporization (H°vap) of acetonitrile (CH3CN) is 34.2 kJ/mol.
The normal boiling point of acetonitrile is 81.6°C.
Calculate the vapour pressure of acetonitrile at 61.1°C.

Which of the following statements is true about the ionization energy of Mg+?

A) It will be equal to the ionization energy of Li.

B)  It will be equal to and opposite in sign to the electron affinity of Mg.

C)  It will be equal to and opposite in sign to the electron affinity of Mg+.

D)  It will be equal to and opposite in sign to the electron affinity of Mg2+.

E)  none of the above

The statement that the first ionization energy for an oxygen atom is lower than the first ionization energy for a nitrogen atom is

A) consistent with the general trend relating changes in ionization energy across a period from leftto right, because it is easier to take an electron from an oxygen atom than from a nitrogen atom.

B)  consistent with the general trend relating changes in ionization energy across a period from leftto right, because it is harder to take an electron from an oxygen atom than from a nitrogenatom.

C)  inconsistent with the general trend relating changes in ionization energy across a period fromleft to right and due to the fact that the oxygen atom has two doubly occupied 2p orbitals andnitrogen has only one.

D)  inconsistent with the general trend relating changes in ionization energy across a period fromleft to right and due to the fact that oxygen has one doubly occupied 2p orbital and nitrogendoes not.

E)  incorrect.

Place the elements C, N, and O in order of increasing ionization energy.

A) C,N,O

B) O,N,C

C) C,O,N

D) N,O,C

E) none of these

An element has the electron configuration [Kr] 4d^(10)5s^(2)5p^(2).

The element is a(n) A) nonmetal. B)  transition element. C)  metal. D)  lanthanide. E)  actinide.

For which element are the d orbitals completely filled in the neutral atom? A) potassium B)  vanadium C)  phosphorus D)  iron E)  bromine