Which of the following is true? group of answer choices
when objects produce heat energy, they always produce sound energy, too.
when objects produce heat energy, the heat energy always turns into mechanical energy.
when objects produce light energy, they sometimes produce heat energy, too. when objects produce light energy, the light energy always turns into electrical energy.

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