15.What is the shielding effect? a. The neutrons shield protons from the attraction of the electrons from the first energy level.
b. Valence electrons are shared equally between atoms.
c. The repulsion of electrons in the same energy level.
d. The inner-core electrons shield outer-core electrons from the attraction to the atom’s nucleus.

letter d?

Explanation:

the sheilding effect sometimes referred to as atomic shielding or electron sheilding describes the attraction between an electron and nucleus in any atom with more than one electron(that's all i can explain..).

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.

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