The document provides directions for a computer-assisted lesson on thunder and lightning. It outlines the following: - The lesson will cover the topic of thunder and lightning through relevant slides and pictures. - Learners can navigate slides using their mouse and click on textboxes for responses. - The direction provided by the computer should be followed. - Brain teasers and relaxers are included to develop concepts and allow for self-checking with explanations. - At the end, a "Test Your Knowledge" session allows learners to recap the lesson.

1. Thunder and
lightning
Presentation by:
Alphonsa Joseph
Social Science
Reg.No: 16914302003

2. Direction for Computer Assisted lesson
Follow the Instruction given below:
This lesson is about the topic- Thunder and Lightning.
This capsule contain suitable slides related to the concept.
 Relevant Pictures are provided in each slide.
Use mouse (single click) to move to the next slide.
Click on the textbox to get the response.
Please note the direction given by the computer.
Brain Teasers are provided for developing concepts
Brain relaxers are provided for self checking aided with necessary
explanation.
After completing the lesson , the learners can recapitulate the lesson
through ‘Test Your knowledge’ session.

3. What is Lightning and Thunder-
Video clipping

5. Let us observe
the pictures and
identify the
ingredients of
thunderstorm

6. THUNDERSTORM INGREDIENTS
Moisture - Preferably in the lower or mid
levels of the atmosphere
Upper level just stream
can carry pockets of
cold air over moist air,
increasing lift and
instability

7. THUNDERSTORM INGREDIENTS
Source of lift – Agent which lifts the warm, moist air
at the starting of the thunderstorm

8. THUNDERSTORM INGREDIENTS
Instability – Ability for air to accelerate
upward/downward when started up/down

9. Look at the fig. 5 in
which different life
cycles are involved
in the
thunderstorm. From
the figure , identify
the cycles of a
thunderstorm

10. THUNDERSTORM LIFE CYCLE
Cumulus Stage Mature Stage Dissipating Stage
Fig.5

11. The life cycle of thunderstorm are in three ways:
Cumulus stage
 Mature stage
 Dissipating stage

13. What is that bright flash of light that
shoots across the sky during a storm?
It’s lightning, and it’s an enormous
electrical discharge that occurs in the
atmosphere during thunderstorms.
But what exactly causes this
electricity in the sky?

14.  In the process of the
water cycle, moisture
can accumulate in the
atmosphere. This
accumulation is what
we see as a cloud
 Cloud droplets collide
other moisture, that is
in the process of
condensing as it rises.

15.  The importance of these collisions is that electrons are
knocked off of the rising moisture
 The newly knocked-off electrons gather at the lower
portion of the cloud, giving it a negative charge

16. LIGHTNING FORMATION

18. THUNDER

19.  As the rising moisture encounters colder temperatures in the
upper cloud regions and begins to freeze, the frozen portion
becomes negatively charged and the unfrozen droplets
become positively charged.
 Here, rising air currents have the ability to remove the
positively charged droplets from the ice and carry them to the
top of the cloud.

20.  The cloud then becomes
separated by charges
 It becomes positively
charged at the top and
negative at the bottom
creating an electric field.

21.  The electric field becomes
so large, that it can rip
some of the electrons of
the air molecules, you then
get some electrons and
positive ions - a plasma.

22.  As there are free electrons and positive ions,
this plasma conducts electricity very well
unlike air which is a good insulator, and
electricity will follow the easiest path, so all
the charge from a significant portion of a
cloud will follow this path, creating a huge
spark - a lightning bolt.
 The entire process of a lightning bolt occurs
in a matter of seconds

23. •If you find yourself caught in a lightning storm, the key to
minimizing danger is to get inside and could protect
structure. If you can detect lightning, it may be close
enough to strike you.
•Never stand under a tall or short tree, and avoid being
close to power lines as they’re both excellent conductors of
electricity and could potentially cause death. If not serious
injury.
•Find shelter near or under a stony shelter, say a cavern or
something,. Never stay near windows. Don’t touch electric
oriental surfaces

24. DEFINING THE TERM – THUNDER
THUNDER STORMS ARE PRODUCED
BY CUMULONIMBUS CLOUDS AND
ARE ACCOMPANIED BY LIGHTNING
AND THUNDER.
It Occurs when the atmosphere becomes unstable—when
a vertically displaced air parcel becomes buoyant and
rises on its own.
The ideal conditions include warm, moist air near the
surface and a large change in temperature with height
(large lapse rate)

25. Brain Teaser 1.1
Thunder storms occur when the
atmosphere is stable and calm?
Refer brain relaxer 1.1 Click
here

26. Wrong
Answer

28. The thunderstorm happens
when the atmosphere is
unstable and the conditions of
warm, moist air near the
surface and a large change in
temperature with height

29. Thunderstorm Hazards
 Lightning
 Tornadoes/downbursts
 Hail
 Flash Floods

30. It was the mid of July. I was sprawled on my comfortable bed and watching a
movie, when my mother came in and asked me to get ready to go shopping; she
wanted to collect her bangles from the jewellers. She said that she wanted to
come back before Maghrib.
Fifteen minutes later, we were on the road. The sky had been cloudy since
morning. As it began to drizzle, I became more conscious on the road. I had been
driving fast, so I slowed down to avoid risks. The drizzle changed to sudden
downpour as we neared the shop. People on the road started to run frantically for
shelter. Vehicles slowed down on the road as well.
Suddenly, we heard a very loud crack of thunder followed by a bright flash of
lightning outside my car window. Within a few minutes, roads and streets had
turned into streams and rivers. Many trees were uprooted. The storm plunged the
city into darkness. Advertisement boards began to fall and damage vehicles
around them
A story of thunderstorm hazards

31. Every year 100-200
people die from
lightning strikes

32. There are actually nine cloud-to-cloud strokes for each
cloud-to-ground stroke

33. Cloud-to-Ground
strokes are the most
dangerous.

34. Notice the segmented
pathway to the ground.
Also, some of the
lighting didn’t contact
the ground.

35. Lightning doesn’t always hit
the tallest object…

36. Out on the golf course is NOT a safe place during a thunderstorm.

37. Here are some pictures of thunderstorm hazards. Observe the pictures and
identify what kind of hazards happen due to thunderstorm

38. All thunderstorms are dangerous and
can be associated with a number of
hazards. Heavy rains can lead to flash
flooding events ,one of the primary
causes of death associated with
thunderstorms.
Lightning, which is produced by every
thunderstorm, causes an average of 80
fatalities and 300 injuries each year.

39. ENLARGING THE DEFINITION
The thunderstorms and its effects like
lightning, flooding, hail etc are dangerous
hazards to human beings
Thunderstorms cause
many hazards to humans
D5

40. Brain Teaser 2.2
Do thunderstorms cause destruction of
buildings or houses?
Refer Brain Relaxer 2.2
Click here

43. Thunderstorms and lighting are
natural hazards which cause heavy
damage to human beings

44. DEFINITION
Thunderstorms are the
factor behind lightning,
flooding, hail and
downbursts
D6

45. CONCEPT
FORMATION
C2 Thunderstorms are natural hazards
which emerge due to the instability of
atmosphere and cause heavy damage to
human life

46. UNIT 1
Thunder and lightning
THINKING
SESSION

47. Brain Relaxer 2.1
Read the news
THE HINDU-April 23, 2015
Bihar thunderstorm kills 42
Crops damaged in north-eastern border districts
At least 42 people were killed, more than 100 injured and crops damaged
when a thunderstorm hit the north-eastern border districts of Bihar late on
Tuesday night.
“It was a strong storm with a wind speed of more than 150 kmph. Purnia is the
worst-affected district, with the most people killed,” Chief Minister Nitish
Kumar told presspersons here after an aerial survey of the affected areas.
Officials said the death toll was likely to rise.
Mr. Kumar said the final assessment of damage would be possible only after
officials of the affected districts sent in the details.

48. From the above
news it is clear that
the lightning and
thunderstorm are
hazardous to
human life

49. Brain Relaxer 2.2
Look at the picture

50. After the
thunderstorm and its
hazards, the people
need rehabilitation as
they lost their
belongings

51. Test your knowledge
I Say True or False
1. Thunderstorm and lightning are hazardous to human life
2. Thunderstorms have various life cylcles
3. What are the various hazards caused by thunderstorm?
Answer ………………………………………………………………………….
………………………………………………………………………….

54. Answer Key
a. Flooding
b. Lightning
c. Hail
d. Downbursts