When developing an experimental design, which action would improve the quality of the results?
A. Ensure that it answers a question about cause and effect.
B. Have a different researcher make the measurements
C. Include as many responding variables as possible.
D. Keep the sample size of test subjects to a minimum

am i too late?

explanation:

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.