Astudent is conducting their science experiment on the effect of caffeine on dogs. he has 3 groups of test subjects. the 1st group of dogs receives plain water. the 2nd group of dogs receives 10 mg of caffeine each, and the 3rd group receives 50 mg of caffeine each. he will measure their activity levels by recording how long each dog runs without stopping, after giving them the pills. what is the control group in this experiment?

The control group are the dogs that receive plain water

Explanation:

In every research experiment we need a standard or control group in which we can compare the effects of the treatments. The control group is tested in normal conditions (we always know what’s is going to happen), in this case, the normal condition is that the dog dirk plain water. The tested group is in which we want to know the effect of the treatment, we do not know what is going to happen ( we want to know what happen if the dog consumes caffeine before runs).

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.  

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.