Which of the following elements is commonly found in the Earth's crust, living matter, oceans, and atmosphere? hydrogen , neon gold or bromine?

Modern weaponry has increased the number of deaths in wars and violent conflicts.

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.