Answer: A) highly mobile electrons in the valence shell
Explanation: conductivity in metals is a result of the movement of electrically charged particles—the electrons. These free electrons also known as valence electrons are free to move, and as a result they can travel through the lattice that forms the physical structure of a metal. The presence of valence electrons determines a metal's conductivity. However, several other factors can affect the conductivity of a metal such as impurities, temperature, magnetic fields etc.
Answer:
Neutral atom means the number of protons is equal to the number of electrons.
Explanation:
Refraction is the change in direction of waves that occurs when waves travel from one medium to another. Refraction is always accompanied by a wavelength and speed change. Diffraction is the bending of waves around obstacles and openings.
Answer:
It should be fibre optic cable , buried underground
