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10 science-- optics > nature and sources of light > Flashcards

Flashcards in nature and sources of light Deck (50)
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1

what are the 2 types of light?

natural
artificial

2

light

the only form of energy that can travel like a wave through empty space and through some materials

3

what kind of wave does light behave like?

electromagnetic

4

can you see electromagnetic waves?

no, they are invisible

5

electromagnetic waves can travel through a ______ at the ______

vacuum / speed of light

6

what is the speed of light?

3 x 10 to the power of eight m/s

7

wavelength

distance from the peak of one wave to the peak of the next wave

8

frequency

number of complete wavelengths that pass a given point in one second

9

electromagnetic spectrum

diagram that illustrates the arrangement of electronic waves according to wavelength or frequency

10

low energy= ____ wavelength

long

11

high energy= ____ wavelength

short

12

visible light

any electromagnetic wave that the human eye can see

13

visible spectrum

continuous sequence of different colours together form visible white light

14

luminous source of light

gives off its own natural light

15

artificial source of light

production of light by converting external energy forms (chemical, electrical, thermal)

16

non-luminous source of light

does not give off its own light, may appear bright because of reflection from a luminous object

17

what are 3 types of light emission?

from the sun
from incandescence
from electric discharge

18

light from the sun:
fusion reaction: ______ atoms in the sun's core collide and sometimes ___________

hydrogen / combine or fuse to form

19

light from the sun:
tremendous amounts of ______ is released

energy

20

light from the sun:
energy transmitted to the bases on _________

outer layers of sun

21

light from the sun:
excited atoms release ___________

excess energy

22

light from the sun:
_____ is emitted

light

23

light from incandescence

a light emitted by a very hot object

24

incandescent bulbs are very inefficient at producing light. how much energy used becomes light versus how much energy is lost as heat?

5% light / 95% heat

25

step one of incandescent lighting
__________ runs through Tungsten wire

electrical current

26

step two of incandescent lighting
Tungsten wire heats to what temperature?

3000 degrees Celsius

27

step three of incandescent lighting
____ excites atoms

heat

28

step four of incandescent lighting
atoms release light-- ______ glows

filament

29

light from incandescence
what is the chemical formula for: chemical energy --> heat + light

CnHn + O2 --> CO2 + H2O + energy

30

what is energy made up of (in the chemical formula for incandescence)?

heat, light