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.

when atmosphere interacts with biosphere they focuses on on the sources and sinks of green house gases (ghgs) air pollutants, particular matters, water and energy between the earth's surface and the atmosphere. the biosphere affects the climate. the atmosphere and biosphere are in constant interaction with each other, and all living things rely on gases in the atmosphere for life. organisms such as animals take in oxygen gas form the atmosphere to use in every cell of their body for smooth functioning of daily routine exercises.