Question

An experiment was carried out to answer the question "Does the pH of water affect the growth of radish plants?" Two groups often radish plants were set up. One group was watered with water having a pH of 3.0, and the other group was watered with water having a pH of 7.0. Both groups of plants received the same amount and intensity of light, the same amount of water, and they were grown in the same type of soil. The heights of the radish plants were measured every 2 days for a period of 2 weeks. Which activity might help to increase the validity of this experiment?

Answer 1

Answer:

Receiving the same amount of light intensity and water. Being grown in the same type of soil ensures that the above listed constant variable is maintained to ensure that any changes to rate of plant growth is solely due to changes in pH level.

Explanation:

The variable that u are testing Is change in pH level. Hence, to ensure results are reliable, u need to hold the other variables constant.