[CBSE]Science Course Structure - Class VIII

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Science Course Structure - Class VIII (Theory)





1. Food (Periods - 22)


Crop production


Questions
Crop production: How
are different food crops
produced?

What are the various
foods we get from animal
sources?


Key Concepts
Crop production: Soil
preparation, selection of
seeds, sowing, applying
fertilizers, irrigation,
weeding, harvesting and
storage; nitrogen fixation,
nitrogen cycle.


Resources
Interaction and discussion
with local men and
women farmers about
farming and farm
practices; visit to cold
storage, go- downs; visit
to any farm/ nursery/
garden.


Activities/Processes
Preparing herbarium
specimens of some crop
plants; collection of some
seeds etc; preparing a
table/chart on different
irrigation practices and
sources of water in
different parts of India;
looking at roots of any
legume crop for nodules,
hand section of nodules.


Micro-organisms


Questions
What living organisms do
we see under a
microscope in a drop of
water? What helps make
curd? How does food go bad? How do we
preserve food?


Key Concepts
Micro organisms – useful
and harmful.


Resources
Microscope, kit
materials; information
about techniques of
food preservation.


Activities/Processes
Making a lens with a bulb;
Observation of drop of
water, curd, other sources,
bread mould, orange
mould under the
microscope; experiment
showing fermentation of
dough – increase in
volume (using yeast) –
collect gas in balloon, test
in lime water.


2. Materials (Periods - 26)


Materials in daily life


Questions
Are some of our clothes
synthetic?

How are they
made?

Where do the raw
materials come from?

Do we use other materials
that are synthetic?

Do we use cloth (fabric)
for purposes other than
making clothes to wear?

What kind of fabric do
we see around us?

What are they used for?





Key Concepts
Synthetic clothing
materials.
Other synthetic materials,
especially plastics; usefulness of plastics and
problems associated
with their excessive use.There are a variety of
fibrous materials in use. A
material is chosen based
on desired property.


Resources
Sharing of prior
knowledge, source
materials on petroleum
products.Collection of material
from neighbourhood or
should be part of the kit.


Activities/Processes
Survey on use of synthetic
materials.
Discussion. Testing various materials –
for action of water,
reaction on heating, effect of flame, electrical
conductivity, thermal
conductivity, tensile
strength.


Different kinds of
materials and their
reactions.


Questions
Can a wire be drawn out
of wood?
Do copper or aluminium
also rust like iron?
What is the black material
inside a pencil?
Why are electrical wires
made of aluminium or
copper?


Key Concepts
Metals and non-metals.


Resources
Kit items.


Activities/Processes
Simple observations
relating to physical
properties of metals and
non-metals, displacement
reactions, experiments
involving reactions with
acids and bases.
Introduction of word
equations.


How things change/
react with one another


Questions
What happens to the wax
when a candle is burnt?

Is
it possible to get this wax
back?

What happens to
kerosene/natural gas when it is burnt?

Which fuel is the best?

Why?



Key Concepts
Combustion, flame
All fuels release heat on
burning. Fuels differ in
efficiency, cost etc. Natural
resources are limited.
Burning of fuels leads to
harmful by products.


Resources
"The Chemical History
of a Candle", by
M. Faraday, 1860.
Collecting information
from home and other
sources.


Activities/Processes
Experiments with candles.
Collecting information.
Discussions involving
whole class.


3. The World of the
Living (Periods - 44)


Why conserve


Questions
What are reserve forests/
sanctuaries etc?

How do we keep track of our plants
and animals?

How do we
know that some species are
in danger of disappearing?

What would happen if you
continuously cut trees?


Key Concepts
Conservation of
biodiversity/wild life/
plants; zoos, sanctuaries,
forest reserves etc. flora,
fauna endangered species,
red data book; endemic
species, migration.


Resources
Films on wild life, TV
programmes, visit to zoo/
forest area/sanctuaries
etc.; case study with
information on disappearing
tigers; data on
endemic and endangered
species from MEF, Govt.
of India, NGOs


Activities/Processes
Discussion on whether we
find as many diverse plants/
animals in a ‘well kept area’
like a park or cultivated land,
as compared to any area left
alone. Discussion on
depletion of wild life, why
it happens, on poaching,
economics.


The cell


Questions
What is the internal
structure of a plant –
what will we see if we
look under the
microscope?

Which cells
from our bodies can be easily seen?

Are all cells
similar?


Key Concepts
Cell structure, plant and
animal cells, use of stain
to observe, cell organelles
– nucleus, vacuole,
chloroplast, cell
membrane, cell wall.


Resources
Microscope, onion peels,
epidermal peels of any
leaves, petals etc, buccal
cavity cells, Spirogyra;
permanent slides of
animal cells.


Activities/Processes
Use of a microscope,
preparation of a slide,
observation of onion peel
and cheek cells, other cells
from plants e.g. Hydrilla
leaf, permanent slides
showing different cells,
tissues, blood smear;
observation of T.S. stem
to see tissues; observing diverse types of cells from
plants and animals (some
permanent slides).


How babies are formed


Questions
How do babies develop
inside the mother? Why
does our body change
when we reach our teens?
How is the sex of the
child determined? Who
looks after the babies in
your homes? Do all animals give birth to
young ones?


Key Concepts
Sexual reproduction and
endocrine system in
animals, secondary sexual
characters, reproductive
health; internal and
external fertilisation.


Resources
Counsellors, films,
lectures.


Activities/Processes
Discussion with
counsellors on secondary
sexual characters, on
how sex of the child is
determined, safe sex,
reproductive health;
observation on eggs,
young ones, life cycles.Discussion on Gender
issues and social taboo’s.


4. Moving Things, People and Ideas


Idea of force



Questions
What happens when we
push or pull anything?
How can we change the
speed, direction of a
moving object?
How can we shape the
shape of an object?


Key Concepts
Idea of force-push or
pull; change in speed,
direction of moving
objects and shape of
objects by applying force;
contact and non-contact
forces.


Resources
Daily-life experience, kit
items.


Activities/Processes
Observing and analysing
the relation between force
and motion in a variety of
daily-life situations.
Demonstrating change in
speed of a moving object,
its direction of motion and
shape by applying force. Measuring the weight of
an object, as a force pull)
by the earth using a spring
balance.


Friction


Questions
What makes a ball rolling
on the ground slow
down?


Key Concepts
Friction – factors affecting
friction, sliding and rolling
friction, moving;
advantages and
disadvantages of friction
for the movement of
automobiles, airplanes
and boats/ships;
increasing and reducing
friction.


Resources
Various rough and
smooth surfaces, ball
bearings.


Activities/Processes
Demonstrating friction
between rough/smooth
surfaces of moving
objects in contact, and
wear and tear of moving
objects by rubbing (eraser
on paper, card board,
sand paper). Activities on static, sliding
and rolling friction.
Studying ball bearings.
Discussion on other
methods of reducing
friction and ways of
increasing friction.


Pressure


Questions
Why are needles made
pointed? Why does a
balloon burst if too much
air is blown into it? Why
does an inverted glass/
bottle/pitcher resist being
pushed down into water?
How can air/liquids exert
pressure?


Key Concepts
Idea of pressure; pressure exerted by air/liquid;
atmospheric pressure.


Resources
Daily-life experiences;
E x p e r i m e n t a t i o n -
improvised manometer
and improvised pressure
detector.


Activities/Processes
Observing the dependence
of pressure exerted by a
force on surface area of an
object.

Demonstrating that air
exerts pressure in a variety
of situations.

Demonstrating that liquids
exert pressure.

Designing an improvised
manometer and measuring
pressure exerted by liquids.

Designing improvised
pressure detector and
demonstrating increase in
pressure exerted by a liquidat greater depths.



Sound


Questions
How do we communicate
through sound? How is
sound produced? What
characterises different
sounds?


Key Concepts
Various types of sound;
sources of sound;
vibration as a cause of
sound; frequency;
medium for propagation
of sound; idea of noise
as unpleasant and
unwanted sound and need
to minimise noise.


Resources
Daily-life experiences; kit
items; musical instruments.


Activities/Processes
Demonstrating and
distinguishing different
types (loud and feeble,
pleasant/ musical and
unpleasant / noise, audible
and inaudible) of sound.
Producing different types
of sounds. using the same
source. Making a ‘Jal
Tarang’. Demonstrating
that vibration is the cause
of sound.
Designing a toy telephone.
Identifying various sources
of noise. (unpleasant and
unwanted sound) in the locality and thinking of
measures to minimise
noise and its hazards
(noise-pollution).


5. How Things Work (Periods - 14)


Electric current and circuits


Questions
Why do we get a shock
when we touch an electric
appliance with wet hands?

What happens to a
conducting solution when
electric current flows
through it?

How can we coat an
object with a layer of
metal?


Key Concepts
Water conducts electricity
depending on presence/
absence of salt in it. Other
liquids may or may not
conduct electricity.

Chemical effects of
current.

Basic idea of
electroplating.


Resources
Rubber cap, pins, water,
bulb or LED, cells,
various liquids.

Carbon rods, beaker,
water, bulb, battery.

Improvised electrolytical
cell, CuSO4


Activities/Processes
Activity to study whether
current flows through
various liquid samples (tap
water, salt solution, lemon
juice, kerosene, distilled
water if available).

Emission of gases from
salt solution. Deposition
of Cu from copper
sulphate solution. Electric
pen using KI and starch
solution.

Simple experiment to
show electroplating.


6. Natural Phenomena (Periods - 26)


Rain, thunder and lightning


Questions
What is lightning?What safety measures
should we take against
lightning strikes?


Key Concepts
Clouds carry electric
charge. Positive and
negative charges,
attraction and repulsion.
Principle of lightning
conductor.


Resources
Articles on clouds and
lightning; kit items.


Activities/Processes
Discussion on sparks.
Experiments with comb
and paper to show
positive and negative
charge. Discussion on
lightning conductor.


Light


Questions
What are the differences between the images
formed on a new utensil
and an old one? Why is
there this difference?
When you see your image
in the mirror it appears as
if the left is on the right –
why?
Why don’t we see images
on all surfaces around us?
What makes things visible?

How do we see images of
our back in a mirror?

Why do we sometimes see
colours on oil films on
water?

What is inside our eye that
enables us to see?

Why are some people
unable to see?



Key Concepts
Laws of reflection.

Characteristics of image
formed with a plane
mirror.

Regular and diffused
reflection.
Reflection of light from
an object to the eye.

Multiple reflection.

Dispersion of light.

Structure of the eye.

Lens becomes opaque,
light not reaching the eye.
Visually challenged use
other senses to make
sense of the world
around.

Alternative technology
available.

Role of nutrition in
relation to blindness


Resources
Mirror, source of light, ray source (mirror covered
with black paper with a
thin slit).

Plane glass, candle, scale.

Experience.

Mirrors and objects to be
seen.

Plane mirror, water.

Model or chart of the
human eye.

Experiences of children;
case histories.
Samples of Braille sheets.


Activities/Processes
Exploring laws of reflection using ray source
and another mirror.

Locating the reflected
image using glass sheet
and candles.

Discussion with various
examples.
Activity of observing an object through an object
through a straight and
bent tube; and discussion.
Observing multiple
images formed by mirrors
placed at angles to each
other.

Making a kaleidoscope.
Observing spectrum
obtained on a white sheet
of paper/wall using a
plane mirror inclined on a
water surface at an angle
of 450.

Observing reaction of
pupil to a shining torch.
Demonstration of blind
spot.

Description of case
histories of visually challenged people who
have been doing well in
their studies and careers.
Activities with Braille sheet.


Night sky


Questions
What do we see in the sky
at night? How can we
identify stars and planets?


Key Concepts
Idea about heavenly
bodies/celestial objects
and their classification –
moon, planets, stars,
constellations.
Motion of celestial objects
in space; the solar system.


Resources
Observation of motion
of objects in the sky
during the day and at night;
models, charts, role-play
and games, planetarium.


Activities/Processes
Observing and identifying
the objects moving in the
sky during the day and at
night.

Observing and identifying
some prominent stars and
constellations.

Observing and identifying
some prominent planets,
visible to the naked eye,
(Venus, Mars, Jupiter ) in
the night sky and their
movement.

Design and preparing
models and charts of the
solar system,
constellations, etc. Roleplay
and games for
understanding movement
of planets, stars etc.


Earthquakes


Questions
What happens during an
earthquake? What can we
do to minimise its effects?


Key Concepts
Phenomena related to
earthquakes.


Resources
Earthquake data; visit to
seismographic centre.


Activities/Processes
Looking at structures/
large objects and guessing
what will happen to them
in the event of an
earthquake; activities to
explore stable and
unstable structures.


7. Natural Resources


Man’s intervention in
phenomena of nature


Questions
What do we do with
wood?

What if we had no
wood?

What will happen it we go
on cutting trees/grass
without limit?

What do we do with coal
and petroleum?

Can we create coal and
petroleum artificially?


Key Concepts
Consequences of
deforestation: scarcity of
products for humans and
other living beings,
change in physical
properties of soil,
reduced rainfall.

Reforestation; recycling
of paper.

Formation of coal and
petroleum in nature.
(fossil fuels?).

Consequences of over
extraction of coal and
petroleum.


Resources
Data and narratives on
deforestation and on
movements to protect
forests.

Background materials,
charts etc.


Activities/Processes
Narration and discussions.
Project- Recycling of
paper.

Discussion.


Pollution of air and
water


Questions
What are the various
activities by human beings
that make air impure?

Does clear, transparent
water indicate purity?


Key Concepts
Water and air are
increasingly getting
polluted and therefore
become scarce for use.
Biological and chemical
contamination of water;
effect of impure water
on soil and living beings;
effect of soil containing excess of fertilisers and
insecticides on water
resources. Potable water.


Resources
Description of some
specific examples of
extremely polluted rivers.


Activities/Processes
Case study and discussion.
Purification of water by
physical and chemical
methods including using
sunlight.

Discussion on other
methods of water
purification.
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