Which of the following is true regarding activation energy? a. it is required only in endothermic reactions. b. it does not hold up a reaction from starting. c. this energy usually comes in the form of light or heat. d. it is required only in exothermic reactions.

The correct option is C.
Activation energy is the energy barrier that must be overcome before a chemical reaction can take place. It is the minimum amount of energy that the reacting species must possesses in order for the reaction to occur. Activation energy may be in form of light or heat.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

What does that mean you dum bum