A piece of chalk, has an initial mass of 43. 5 grams. The mass of the chalk decreased to 39. 6 grams after use. Which of these is the closest value to the amount of chalk used?.

chemistry sucks a**

explanation:

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

a:

by the combination of an unlimited number of elements