C.) both secrete toxins and have thorns (It simply depends on what kind of plant it is)
It is covalent bonding. The electrons are shared between the phosphorus and the chlorines.
covalent bonding is when electrons are shared between two elements.
molecular polarity is a little bit complicated, but I will try to explain ;)
PCl3 is an alternation on tetrahedral molecules.
It means that P has one lone pair of electrons. This pair of electrons are only attracted to the P nuclei and thus a greater freedom of motion.
This means that their orbital is bigger and this pushes the 3 Cl atoms closer together.
The angle between each Cl now is 107 and the angle between Cls and P is greater than 107.
Now, due to this shape, and also electronegativity (Cl is more electronegative than P meaning that it tends to hog the electrons they share closer to itself), PCl3 is polar. Electrons that are shared tend to flow closer towards the Cl than the P side.
Therefore, on the Cl side of the molecule it's, more negative. On the P side, it's more positive.
I would believe sunlight to be an independent variable as the sunlight is the control of the whole experiment. You can tell because he placed one in a dark area and the other in a sunny area.
The dependent variable would be: Growth
Controls: The air-conditioning in both rooms
It is not constant because this would be the variable that would remain the same, for example, the type of plant was kept the same.
Hope this helps c: