ANSWER:
Physical chemistry is the branch of chemistry that deals with the physical structure of chemical compounds, the way they react with other matter and the bonds that hold their atoms together. An example of physical chemistry is nitric acid eating through wood.
There must be effective collisions between the reacting chemical particles in order for the chemical reaction to occur.
A solution of KNO3 consists of ions of potassium and nitrate. The ionic equation is expressed as:
KNO3 = K+ + NO3-
There is 1 is to 1 ratio between the substances. So, the molarity of NO3- in the solution is calculated as follows:
0.160 mol / L KNO3 ( 1 mol NO3- / 1 mol KNO3 ) = 0.160 M NO3-
B, millimeters because paper is really thin therefore it'd require small measurements for units.