All life must maintain an internal balance, despite environmental changes. this is called

Apart of the periodic table is shown. a portion of the sixteenth and seventeenth columns of the periodic table is shown. column 16 reads eight oxygen, 16 sulfur, and 34 selenium. column 17 reads nine flourine, 17 chlorine, and 35 bromine. which of the following elements is less reactive than the others? bromine (br) oxygen (o) selenium (se) sulfur (s)

20 the compound al(nh3)2 has atoms of nitrogen.

Which ocean is on the eastern coast of north and south america? arctic ocean indian ocean pacific ocean atlantic ocean