A closed system is a system that makes no physical or chemical exchanges with its environment. Of these systems provided as choices (tree, human, clock, car), only a clock does not make exchanges with the environment, except for energy.
Therefore, of that list, only a clock would be a closed system.
Hope that helped! =)
It’s an Element. Because each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e. the number of protons in the nuclei of its atoms.
Answer:Ais the answer
Explanation:
I passed biology last year and that’s something I remember
The answer is <span>B. The type of fertilizer.</span>
<span>An independent variable is variable that is not affected in the
experiment. It is what experimenter controls. On the other side, a dependent
variable is called dependent because it depends on the independent variables.
It is what is affected during the experiment.
In this case, the growth of pea plants depends on different types of
fertilizer. So, the growth of pea plants is the dependent variable and different
type of fertilizer is the independent variable.</span>