Question

How many states are in the n = 4 shell?

4

9

16

18

32

If a solid has a half-filled valence band, which of the following would it be?

a conductor

an insulator

a semiconductor

a p-type semiconductor

an n-type semiconductor

If an element has a band gap of 1 eV between a filled valence band and an empty conduction band, it would be classified as a(n)

insulator.

conductor.

resistor.

semiconductor.

reactor.

If the momentum of a particle is doubled, what happens to its de Broglie wavelength?

it doubles

it halves

it slightly more than doubles

it becomes slightly less than half it decreases by a factor of 2-1/2

Answer 1

n = 4 can take s, p , d and f orbitals...so, it can have 4 states

---------------------------------------------------------------------------------------------

A partially-filled valence band is also called the conduction band, since electrons in that band can be responsible for conduction, so it will be a conductor

------------------------------------------------------------------------------------------

I think the answer for this is semiconductors as they have forbidden gap of about 1 eV between valence band and conduction band

---------------------------------------------------------------------------------------------

We know that

$\lambda$ = h/p

so, if  momentum of a particle is doubled, the de Broglie wavelength halves.