3. Distinguish between a complex substance and an elemental substance.
A1, A2a
4. (a) What are the two general classes of ele
ments? (b) Do all elements fit definitely int
one of these classes? A1, A2e
5. Distinguish between a compound and
mixture. A1, A2, A5a
6. What are the five most abundant element
by mass in the earth's surface environment
A3d
7.) (a) What are the properties of metals? (b)
nonmetals? A2e​

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

m=9

step-by-step explanation:

catya that's not even a b or c

you gotta add the following molecules so we can give u an answer

explanation: