The ability or power to transmit heat, electricity, or sound
(hint: 12 letter)

Conductivity

Explanation:

It is the ability to transmit heat, electricity or sound.

Conductivity

Explanation:

The measure of an electricity or heat can pass through a material.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.