Design a scientific experiment, complete with all of the steps of the scientific method. it doesn't have to be complicated. it could be a cooking experiment, a gardening/growing experiment, etc. make certain you have a strong hypothesis that can be tested.
i will give 30

Scientific question:

Does light intensity effect the growth of a plant?

Hypothesis:

If the light intensity is increased, then the plants will grow more.

Experiments and observation:

Place a plant in dark, take three other plants and vary the amount of light intensity in them. For plant 1, the light could be given for 2 hours a day. For plant 2,the light could be given for 4 hours a day. For plant 3, the light could be given for 6 hours a day.

Results:

We see that the plant which received 6 hours of light grew more.

Conclusion:

The hypothesis is correct. The light intensity effects the growth of plants. Plants which receive more light grow more.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.