Salt=compound, soda=liquid solution, aluminum foil=element, milk=colloid,
steel=solid solution
Although 1013.25 mb (760 mm Hg) is considered to be the standard atmospheric pressure at sea level, it does not mean that the pressure at this level has this value, actually this being 1011 mb.
A, because the number of valence shell electrons (outer shell electrons) tells us how much the element or compound wants to bond or give up electrons. Most compounds and elements want to have eight valence ectrons in it's outer ring. So if an atom is far away from having eight, it will want to react more often.
