Chapter 26 Properties of Light

Question 1

Electromagnetic wave

Answer 1

An energy-carrying wave emitted by a vibrating charge (often electrons) that is composed of oscillating electric and magnetic fields that regenerate one another.

Question 2

Electromagnetic spectrum

Answer 2

The range of electromagnetic waves extending in frequency from radio waves to gamma rays.

Question 3

Transparent

Answer 3

The term applied to materials through which light can pass in straight lines.

Question 4

Opaque

Answer 4

The term applied to materials that absorb light without reemission and thus through which light cannot pass.

Question 5

Shadow

Answer 5

A shaded region that appears where light rays are blocked by an object.

Question 6

Umbra

Answer 6

The darker part of a shadow where all the light is blocked.

Question 7

Penumbra

Answer 7

A partial shadow that appears where some but not all of the light is blocked.

Question 8

Solar eclipse

Answer 8

An event wherein the Moon blocks light from the Sun and the Moon’s shadow falls on part of the Earth.

Question 9

Lunar eclipse

Answer 9

An event wherein the Moon passes into the shadow of the Earth.