Scientific Method

Indep. Variable
Dependant Variable
Constants
Notes/Hypothesis

1
Water Temperature
Dissolved Oxygen Level
Water quantity, time, container material
If you lower water temperature, then the dissolved oxygen levels remain acceptable.

2
pH
survival of brine shrimp
10 Shrimp, water, plastic tubing, time
If the solution is to acidic, then the shrimp will not survive. (When HCL and KOH mix, they become a neutral solution. Therefore, the testing is not valid.)

3
Number of radish seeds
Amount of biomass
Amounts of water, sunlight and soil
If there are more radish seeds, there will be more biomass

4
CuSO4
Death of Shrimp at 50%
24 and 48 hour checks
#of shrimp
If 1% sol of CuSO4 is used then 50% of brine shrimp will die within 48 hours.

5
The 5 different herbicides
Dead grass/weeds
amount of sun, time, water, grass and spray
If herbicide x is used, then a greater amount of weeds will die (multiple independent variables used)