Answer:
Noble Gases.
Explanation:
The reason why I say this is due to them having eight valence electrons, their outer energy levels are full.
Contain structures that regulate and perform life functions.
Answer:
Cells come from other living cells
All living things are composed of one or more cells
The cell is the basic unit of life.
Because if we're simultaneously moving/manipulating two different variables it can be very hard to determine why one variable is changing and why the other is changing. While this can be done with more complicated experimental designs, it usually is the case that scientists will only manipulate one variable and not two different ones.
