3a day 2 revision points

If an atom has gained an electron, it is:

• positive ion

• negative ion

What happens to the charge of an atom if there are equal number of protons and electrons?

• positive

• negative

• neutral

Conventional current flow is from ___________ to ___________

• negative to positive

• positive to negative

A free electron occurs (and therefore current flows) when the energy level is in which band?

• valence band

• conduction band

What is the conductor most often used because of it's availability and relative cost?

• iron

• silver

• copper

• gold

Semi-conductors have how many valence electrons?

• 1-3

• 4

• 5-8

Which of the following is an insulator?

• rubber

• gold

• germanium

• silicon

Contact, Friction/pressure and __________ are the major causes of static electricity?

• separation

• temperature

• electromotive force

Materials further apart on the triboelectric series are ____ likely to develop greater static electricity.

• more

• less

If you double the length of a wire and keep all other factors the same, what happens to the resistance?

• doubles

• halves

• no effect