Select all the correct answers. Regina is testing this hypothesis:
Higher relative humidity leads to faster growth in orchids.

She has designed an experiment in which she will grow orchids in terrariums of varying humidity levels. She will then observe how the humidity affects the growth of the plants.

Which of the following variables are the confounding variables that Regina should control for before beginning her experiment?

1.the amount of sunlight the plants receive

2.the temperature at which the plants grow

3.the type of soil in which the plants grow

4.the growth rate of each of the plants

5.the relative humidity inside each terrarium

1,2,&3

Explanation:

four and five would not qualify as confounding variable‘s

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-