6. as you go down a family or group on the periodic table *
1 point
the atoms become smaller and smaller.
the elements become less reactive.
the elements become more reactive.
the atoms have more and more valence electrons

None of the given statements are completely true.

Explanation:  

Family or groups in "periodic table" are 18 in number which represents column in table. As we go down in a family or group in the "periodic table"-the atom size become bigger and bigger. Non-Metals are less reactive which mostly lie in p-block. "Metals" are ""ore reactive" in "s-block". The atom’s valence electrons remain same for example when we go down in alkali metals in s-block the valence electron is one only and in alkaline earth metals its two only.

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.