development of hypotheses

hypothesis 2

The increase in atmospheric CO2 is due to the increase in the amount of fossil fuels that are being burned. Usually, testing a hypothesis requires making observations or performing experiments. In this case, we will look into the scientific literature to see if we can support or refute either or both of these hypotheses. Click image to the left or use the URL below. URL:

hypothesis 1

Atmospheric CO2 has increased over the past five decades, because the amount of CO2 gas released by volcanoes has increased.

asking a new question

Before we develop some hypotheses, lets find a new question that we want to answer. What we just learned that atmospheric CO2 has been increasing at least since 1958. This leads us to ask this question: Why is atmospheric CO2 increasing?

possible answers for the question

We do some background research to find the possible sources of carbon dioxide into the atmosphere. We discover two things: Carbon dioxide is released into the atmosphere by volcanoes when they erupt. Carbon dioxide is released when fossil fuels are burned. A hypothesis is a reasonable explanation to explain a small range of phenomena. A hypothesis is limited in scope, explaining a single event or a fact. A hypothesis must be testable and falsifiable. We must be able to test it and it must be possible to show that it is wrong. From these two facts we can create two hypotheses. We will have multiple working hypotheses. We can test each of these hypotheses.

instructional diagrams

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the law of conservation of energy says that energy cannot be created or destroyed.

-->  a) true

b) false

which one of these is an example of chemical energy?

-->  a) a match lighting a candle

b) kicking a ball

c) going down a slide

d) pedaling a bicycle

which one of these is not an example of potential energy?

a) a ball sitting at the top of a hill

b) a batter ready to hit a ball

-->  c) the kick of a leg on a soccer ball

d) an apple hanging from a tree

burning fuel is an example of using this kind of energy.

a) potential energy

b) kinetic energy

c) electrical energy

-->  d) chemical energy

kinetic energy is energy associated with the movement of atoms or molecules that can be transferred.

a) true

-->  b) false

which of these is an example of chemical energy?

a) food is fuel for the body

b) sunlight to make energy for plants during photosynthesis

c) gasoline as fuel for cars

-->  d) all of the above

where does energy come from?

-->  a) fuel

b) heat

c) photosynthesis

d) gasoline

animals and plants get energy directly or indirectly from the sun.

-->  a) true

b) false

if a person eats a sandwich in a park on top of a hill, stands on their bike at the top of the hill, and then rides the bike down, the energy conversions are

a) kinetic to potential to chemical

-->  b) chemical to potential to kinetic

c) chemical to kinetic to potential

d) potential to kinetic to chemical

diagram questions

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