NEIS October branch

Science department
Grade 7 U4 P1

COLOR unit 4

Subject Grade Date Block week Unit/Lesson/Topic classwork

Science 7 /11/2023 2 4 color 1 out of 1

• Use prisms to investigate the white light coloures ( page 6)

• Identify light dispersion using prism. ( page 7)
• Recall colours forming white light in order
(spectrum colours) ( page 7)
• Draw a diagram showing dispersion of white light
through prism.(page 7)
• Explain how refraction of light occur. (page 5)
• investigate what happens to the dispersion of white light
when the angle of incidence is changed. page (7)
• Show understanding for the ray diagrams of
the normal line, angles of incidence and angles
Learning Outcome of refraction. (page 5)
/Objec2ve: • Recall the different spectrum colors. (page 6)
• Recall the meaning of reflection.(page 4)
• Define the meaning of absorbing light. (page 9)
• Explain how objects can absorb or reflect light. (page 10)
• Explain why we see different colored objects in white
light using the terms absorb and reflect. (page 10)
• Differentiate between colored object that reflect and
absorb light. (page 11)
• Draw a labeled diagram showing white, black and
colored objects that appear under white light. (page 12)
• Recall the terms (transparent – translucent – opaque)
• Identify colour filters. (page 9)
Student Name: ……………………………………………………………………………………………………………………………………. Class 7……..

Prepared by Mr.Ahmed Ramadan 1

NEIS October branch
Science department
Grade 7 U4 P1

COLOR unit 4

Subject Grade Date Block week Unit/Lesson/Topic classwork

Science 7 /11/2023 2 4 color 1 out of 1

• Explain how colored filters behave when white light

or different colored light fall on it. (page 11)
• Provide examples to show how colored filters behave
when white light or different
colored light fall on it. (page 11 )
• Identify what happens when a combination of filters are
used with white light or colored lights (page 12)
• Set investigation to test how colored filters behave
when white and different colored lights are shone
Learning Outcome through them. (page 10)
/Objec2ve: • Draw a labeled diagram to show how colored filters
behave when white and different colored lights are
shone through them.(page 10)
• Investigate what happens when two different colours
add together.
• Identify how adding primary colours (red- green – blue)
of white light together produce white light and
secondary colours (cyan -magenta- yellow) page 8

Student Name: ……………………………………………………………………………………………………………………………………. Class 7……..

Prepared by Mr.Ahmed Ramadan 2

NEIS October branch
Science department
Grade 7 U4 P1

COLOR unit 4

Subject Grade Date Block week Unit/Lesson/Topic classwork

Science 7 /11/2023 2 4 color 1 out of 1

State some examples of colored objects in colored light.

• Explain how different colored objects appear
under different colored lights (use terms of absorb –
reflect (page 11)
• Investigate how different colored objects appear under
different colored lights (use terms of absorb –
reflect) page (12)
• Draw a labeled diagram showing white, black and
colored objects appear under colored light. (page 10)
• Investigate the relationship between distance and
brightness of light. (page 14)
Learning Outcome • Identify the relationship between light intensity and
/Objec2ve: distance. (page 14)
• Draw graph to interpret the relation between intensity
of light and distance (page 14)

Student Name: ……………………………………………………………………………………………………………………………………. Class 7……..

Prepared by Mr.Ahmed Ramadan 3

 Reflection When you think of reflection you probably think of using a mirror.
Most of the mirrors you use are plane mirrors, (Plane) means flat.

Remember that light travels in straight lines called rays.

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 Dispersion
Dispersion means splitting light into different colours. Dispersion happens because
light is refracted. Each of the different colours of light that make up white light
is refracted through a slightly different angle. This can be shown by using a
triangular prism.

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 When a ray of white light passes through the prism, the ray is refracted.

Violet light is refracted through the largest angle and

red light is refracted through the smallest angle.

What happens to the dispersion of white light when the angle of

incidence is changed?

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 Primary colours:

(Seven colours in white light are the colours that can be seen in the rainbow.),
However, there are three colours of light from which all other colours of light can
be made. These are called the primary colours.

The primary colours cannot be made by mixing any other colours of light.

The primary colours of light are:

• Red • Green • Blue.
The primary colours of light are different from the primary colours in paints.

You can see the effect of adding the primary colours

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 You can use coloured filters to remove colours from light. If a transparent piece of
coloured glass or plastic is placed in front of a white light, then only light of that
colour will be transmitted (get through). All the other colours will be absorbed.

A common example of coloured filters is in traffic lights.

The traffic lights use three identical white lamps. In front of each lamp is a
coloured filter for red, yellow, or green.

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 Take the red filter as the example to see how this works. White light, from the
lamp, is made from the seven colours of light: red, orange, yellow, green, blue,
indigo, and violet. When these seven colours arrive at the red filter, only red is
transmitted. The other six are absorbed.

The blue stage light in the picture has a white lamp and a blue filter.

If you look carefully, you can see where the white lamp is inside the black case.

The colours of the filters in stage lights can be changed to produce different
colours.

If white light shines on a green filter, only green light will get
through. The other colours of the white light are absorbed. If this
green light, then shines on a red filter then no light will get
through. Green is one of the colours that a red filter absorbs.

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 Seeing colours
When you look at a non-luminous object, you see the light that is
reflected from the object. ‘Non-luminous’ means the object does not
emit its own light. Look at the flower in the picture. The flower is seen
in white light. The flower looks yellow because it reflects only yellow
light. The flower absorbs the other six colours in white light.

A white object reflects all the colours in white light equally. A black
object absorbs all the colours in white light and does not reflect any.
These three balls appear black, red, or white, according which colours
of light they reflect and which they absorb.

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 • Seeing colored objects through white light:

The colour an object appears depends on the colours of light it

reflects.
- Coloured objects reflect only its colour.

- Whit objects reflect all light colors.

- Black objects absorb all light colors.

For example, a red book absorbs all light colours and reflects red light:

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 • Coloured objects in coloured light
- An object appears to be black if it absorbs all visible light. For
example, an object that appears blue in white light will appear
black in red light. This is because the red light contains no blue
light for the object to reflect.
- The table gives some more examples, displaying the colour of
light shining on an object, the colour(s) absorbed by an object,
the colour reflected by an object in this light and the colour of
an object seen in this light.

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 More on Brightness as a Function of Distance
light and other waves travel, the energy they carry usually becomes
more spread out
The intensity or brightness of light as a function of the distance from
the light source follows an inverse square relationship. Suppose you
were to use a light meter to measure an initial intensity (I), or
brightness, a distance r from a light source. Suppose that sometime
later the brightness of the light is either greater or lesser; if the
intensity diminished you would know that the source was moving away
from you and if it became brighter, you would know that the source
was moving towards you (assuming the light source itself remained the
same).

The intensity or brightness of

light as a function of the distan ce

from the light source follows

an inverse square relationship

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