21. How long of a line should you draw to represent 500um if the diameter of the circle on your paper is 20mm, the length of the desired scall is 1000um, and the field of view is 5000um?
22 Demonstrate the adiurtmont
ucing alonch

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.