This chart shows the experimental design of four students who are all observing what kind of bird seed birds tend to eat more often.

Student 1
- Performed the experiment once
- Used the same area, same time of day, and same amount of seeds
Student 2
- Repeated the experiment 5 times
- Used the same area, different time of day, and different amount of seeds
Student 3
- Repeated the experiment 2 times
- Used the same area, different time of day, and different amount of seeds
Student 4
- Repeated the experiment 5 times
- Used the same area, same time of day, and same amount of seeds

Which student is the most likely to have reproducible results?

Student 1
Student 2
Student 3
Student 4

Student 2

Explanation:

Student 2 repeated the experiment several times with different seeds to make sure the experiment would come out with the same answers and was reliable, using the same area would make sure the environment wouldn't interfere. The other students didn't do all the things that student 2 needed for the experiment.

Student 2

Explanation:

Student 2 repeated the experiment with different seeds at different times 5 different times, ensuring he/she got the most reliable answers.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e