Colour

Page
3

Slide 18

Blue

BLUE

Blue pigment reflects not only blue light, but also colors to either side of blue namely, green and violet. It absorbs red orange and yellow light.

Red , orange, and yellow have been subtracted from the incident light.

Slide 19

Why the Sky is Blue

Nitrogen and oxygen molecules ring like tiny bells with high frequency when energized by sunlight.

Reemit light in all directions like the sound of a bell.

Atom

Scattered Radiation

Incident Beam

Slide 20

28.8: cont…

Ultraviolet light from the sun is absorbed by the protective layer of the ozone gas.

Visible frequencies of violet light is scattered.

Although the violet light is scattered more, our eyes are only sensitive to blue. That’s why we see a blue sky.

Slide 21

Why Sunsets are Red

Slide 22

28.9: cont…

Lower frequencies of light are scattered the least by nitrogen and oxygen molecules

 Red, orange, yellow are transmitted more readily through the atmosphere

Light of lower frequencies is transmitted while light of higher frequencies are scattered

Slide 23

28.9: cont…

At dawn and sunset, the sunlight reaches the earth at a longer path

At noon, the light travels the least

Blue light is scattered as the path of the sunlight becomes longer

Slide 24

Why Water is Greenish Blue

Water is transparent to almost all the visible frequencies of light.

The color is actually the reflected color of the sky

Red is absorbed by the molecules in the water

Slide 25

Slide 26

The Atomic Color Code- Atomic Spectra

Every element has its own specific glow

The light from the elements can be analyzed by a spectroscope

It is composed of thin slits, lenses, and a prism

It displays the spectrum of light

Line spectrum- images of the slit through which the light passes

Slide 27

Spectroscope

Slide 28

THE END