Which statements describe ecosystems?
1. biodiversity is one way to judge the health of an ecosystem.
2. ecosystems must be balanced to survive.
3. a healthy ecosystem can support an unlimited number of life forms.
4. the parts of an ecosystem exist independently and have little to do with each other.
5. people's activities sometimes improve the health of an ecosystem
6. predators play a role in balancing the earth's ecosystems.

50- 250 is correct i did that one too

step-by-step explanation:

chemists are often responsible for designing a chemical reaction and analyzing the products obtained from it. one significant part of designing a chemical reaction is determining the amount of each reactant that is needed and the amount of each product that will be produced. in order to do so, chemists use stoichiometry, the quantitative relationships between reactants and products.