What is the half-life of the substance as determined by the graph?

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.

Can someone me with questions 12 and 13 plz.

Arectangle has a diagonal 20 inches long that forms angles of 60 and 30 with the sides. find the perimeter of the rectangle. for geometry