Zach wants to run an experiment on reaction rates. He designs an experiment testing the reaction rate changes when magnesium and hydrochloric acid react. He decides to run one trial with magnesium ribbon and 1.0 M HCl. For his second trial he rolls the magnesium ribbon into a tight coil and reacts it with 2.0 M HCl. In the third trial, Zach cuts the same amount of Magnesium into slivers and reacts them with 3.0 M HCl.

What is the problem with Zach's experimental design?
Question 13 options:

Human error is uncontrolled.

There is no problem with his design.

There are two variables in each trial.

The concentration of the acid is too dilute.
Question 14 (0.4 points)

Blood is a connective tissue composed of red blood cells, white blood cells, and blood platelets. Why is it that we can see blood cells only with a microscope?
Question 14 options:

The cells form clumps.

The cells keep moving about.

The cells have different shapes.

The cells are very small in size.
Question 15 (0.4 points)

Consider the chart describing the element. According to the chart, the element is with an atomic number of .

Question 15 options:

neon; 3

boron; 4

lithium; 3

nitrogen; 7
Question 16 (0.4 points)

Baking soda is often used in experiments to neutralize vinegar. In the picture above, the beaker on the left contains a solution of vinegar. What can you conclude about the picture on the right?
Question 16 options:

The solution on the right has a pH less than 7.

The solution on the right will not conduct electricity.

It has similar characteristics as HCl and H2SO4.

It must be a base since is has the opposite reaction to litmus paper as vinegar and vinegar is an acid.