Asap test monday

what word best describes the ph at which the speed of a reaction involving an enzyme occurs best?

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight.which of these is the most likely effect on the ecosystem? a-an increase in biodiversity. b-an increase in immigration to the area. c-a decrease in available water. d-a decrease in plant growth.

In what for do plants utilize nitrogen? why do they need nitrogen?

Which chemical equation is unbalanced? which chemical equation is unbalanced