In the ground state, an atom of which element has seven valence electrons?
1.
sodium
2.
phosphorus
3.
nitrogen
4.
fluorine

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

All of the following are homogeneous mixtures except a) sugar dissolved in water. b) orange juice. c) coffee with cream. d) household vinegar. e) apple juice

The bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?