What are valence electrons? A. Electrons with a positive charge
B. The same as the numbers of protons
C. The total number of electrons
D. Electrons in the outermost energy level

D

Explanation:

Valence electrons are the electrons in the outermost shell or last energy level of an atom. Valence electrons are electrons in the highest principal energy level. They are electrons that sit on the outermost orbit of an element. They are responsible for bonding and chemical properties of each element

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.