Which of these elements is an alkaline earth metals? a. hafnium (hf) b. radon (rn) c. silicon (si) d. sulfur (s)

This active feature of earth's crust in building mountain ranges as well as islands. this feature is a a) cavern. b) earthquake. c) mountain. d) volcano.

According to coulomb's law, how would the electrical force between particles change if the product of their electrical charge increased?

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?