Answer:
A student can measure the number of gas bubbles given off by the algae.
Explanation:
- Photosynthesis is the process where green plants convert light energy into the fuel energy for their development and activities.
- Algae is also involved in the photosynthesis process, so the it releases the gas bubbles.
- The oxygen emission process is done by secreting the bubbles by green plants during photosynthesis process.
- So to know about the photosynthesis rate the number gas bubbles, really helps a lot.
This one can be tricky, because your are changing the appearance of the substance. But here, you aren't changing its chemical form, so its a physical change. Even though you can't bring the pencil to its original beginning, its still a physical change.
Answer: Physical change.
For the environmental risk, it is much better to prevent pollution than to deal with it after it has already been made. When you deal with the pollution, it is hard to say that you can eliminate completely. So, prevention is the first strategy.
Answer:plants
Explanation:the greener and more vegetated ecosystem is more healthier with plenty of habitat,food and moisture provided for other living organisms and also attracting agents like pollinators .
