8. What is an energy level? A)The region outside the nucleus where the neutron is likely to be moving.
B)The region outside the nucleus where the electron is likely to be moving.
C)The region outside the nucleus where the proton is likely to be moving.
D)The region inside the nucleus where the electrons are located.

B. The region outside a nucleus where the electron is moving

Explanation:

The more the electron moves, the higher energy level it has, the slower the electron moves the lowwer energy level it has.

Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels.

:D

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.