3. Conductors
are materials that allow heat
and electricity to pass through
easily. Copper wires are widely
used for electrical wiring
because they are ductile and are
good conductors of electricity.
Iron, gold, silver, brass, steel,
nickel and water are also
conductors of heat and
electricity.
4. Metals are good
conductors of heat and
electricity. Copper and
aluminum are metals.
Stainless steel is an iron-
based metal with chromium.
Cooking pots and pans made
of metals make cooking faster
because they quickly allow
heat transfer from the flame
to the food being cooked.
26. The light that is visible to the human
eye is called visible light.
What is LIGHT?
It is the small part of the electromagnetic
spectrum which affects our vision.
27. The SUN is the primary source of visible light.
What is the primary source
of visible light?
28. The visible light allows us to see the color that is not absorbed
by the objects.
For example, you see most plants as green because the leaves
absorb all colors of the visible light except for green.
29. Optics is the study of
refraction, reflection,
absorption, and
transmission of light.
30. Refraction
It refers to the bending of
light as it passes
through different
materials.
https://www.youtube.com/watch?v=9n362snGUdw
https://www.youtube.com/watch?v=jQDRNb-E-cY&t=16s
36. Reflection
It refers to the bouncing
back of light when it hits
an object. Some objects
with flat surfaces, like
mirrors, reflect light in a
straight way.
https://www.youtube.com/watch?v=skGmQC87Bvg
37. Reflection
The light hits your body.
Your body will reflect the light
and will strike the mirror.
The light from the mirror will be
reflected or bounce back
and reaches our eyes.
43. Transparent materials
allow all lights to pass
through them. Clear
plastic and glass windows
are examples of
transparent objects.
44. Translucent materials allow
some light to pass through
them. Stained glasses and
frosted windows are
examples of translucent
objects.
45. Opaque materials do not
allow light to pass
through them.
Concrete walls, wooden
doors, and mirrors are
example of opaque
objects.
46.
47. Matching Type. Match the definition in Column A with the concept in Column
B. Write the letter of your answer on the space provided before each number.
Column A Column B
______1. primary source of light a. sun
______2. the light that is seen by the human eye b. refraction
______3. the bending of light as it passes through c. reflection
a different material d. opaque
______4. the bouncing back of light when it hits e. visible light
an object f. transparent
______5. objects that do not allow light to pass
through them