Half Life & Solar Power

Question 1

What is a half-life?

Answer 1

The amount of time that it takes for 1/2 of a radioactive isotope to decay

Question 2

What are isotopes?

Answer 2

Atoms that have the same number of protons but different numbers of neutrons

Question 3

What is a photovoltaic cell?

Answer 3

A device that converts light energy directly into electrical energy

Question 4

Which element is the “heart” of a photovoltaic cell?

Answer 4

Silicon

Question 5

T/F: Light of certain energies can free an electron between silicon atoms in a solid

Answer 5

True

Question 6

Silicon is not an electrical conductor.

Answer 6

False

Question 7

Doping

Answer 7

The process of adding small dopants of other elements to pure silicon.

Question 8

What is the N-type semiconductor?

Answer 8

When an element such as Arsenic is added to the pure silicon lattice which creates an excess of electrons

Question 9

What is a P-type semiconductor?

Answer 9

When silicon gets replaced with the element Gallium into the lattice, which leaves the lattice with one electron short (-1 electron, +1 Ga)

Question 10

Is it true that only photons with enough energy can knock electrons free from the doped silicon lattice?

Answer 10

Yes, this is true

Question 11

Which type of alternative energy source has seen the largest growth over the last decade?

Answer 11

Wind power

Question 12

Geothermal Energy

Answer 12

The thermal energy in the Earth’s crust (heat that is produced from the depths of the Earth’s core)

Question 13

T/F: Hydroelectric power has generated the most electricity over the time period starting from 2005?

Answer 13

True!