In today’s 7th Science and technology class we started with a
discussion on the differences between resources and substances.
SUBSTANCE:
A substance could be anything or object. When something doesn’t have a
value or utility it’s called a substance.
RESOURCE:
A resource is any substance that is used to satisfy human needs and
demands. It is something that has utility and value. Some resources has
economic value while some don’t.
E.g., Milk has economic value but a beautiful landscape has no economic
value. But both are important because both satisfy some human needs.
Resource can become substance and substance can become resource.
Time and technology are two important factors which can change a
substance into resource.
e.g., Nilavembu, remdesivir, fire, online purchase apps, petroleum etc.
Types of resources:
Natural resource: Resources which are obtained from nature are called
natural resources.
Human made resource: When a natural resource undergoes drastic change by
human intervention, it becomes man made resource.
ENERGY RESOURCES:
RENEWABLE RESOURCES:
Renewable resources are replenished naturally and over relatively short
periods of time.
NON-RENEWABLE RESOURCES:
Non renewable energy comes from sources that will run out or will not be
replenished in our lifetimes. These sources are limited.
Most non-renewable resources are fossil fuels: e.g., coal, petroleum,
natural gas, firewood and nuclear energy Carbon is the main element in fossil
fuels.
COAL:
·
Coal contains mainly carbon. The slow process of
conversion of dead vegetation into coal is called carbonization. More
carbonization leads to more quality of coal.
·
It is the most abundantly found fossil fuel.
·
It is used as a domestic fuel, in industries such as
iron and steel, stream engines and to generate electricity. Electricity from
coal is called fossil fuel.
·
It is also called as buried sunshine.
Types of coal:
·
Peat- 20% of carbon
·
Lignite 40% of carbon
·
Bituminous 60% of carbon
·
Anthracite more than 70% of carbon
Advantage: Extensively available and efficient conversion to
electricity.
Disadvantage: Polluting source and bulky to transport.
FIREWOOD:
It is widely used for cooking and heating . in our country more than
fifty percent of the energy used by villagers come from firewood.
NATURAL GAS:
·
It is mostly made up of methane
·
It is easy to transport through pipes
·
Stored under high pressure as compressed natural gas
(CNG)
·
CNG is used for power generation, fuel for burning and
for domestic purposes
ADVANTAGE:
·
Easier to transport (pipelines).
·
Cleaner than oil and coal.
·
Cheaper than oil.
DISADVANTAGE:
·
Depletion of oxygen due to spillage and gas leakage.
·
Pollutants released caused acid rain.
·
Exploration of new fuel is not easy.
DCredits : Leo B Brindhaa
