下列各组元素按电负性大小排列正确的是( ) A.F>N>O B.O>Cl>F C.As>P>H D.Cl<S<As 答案:解析:A中,F、N、O属于同周期,从左向右,电负性逐渐增大,因此F>O>N。B中,F、O同一周期,F>O,F、Cl同属一主族,同一主族,由上到下,电负性逐渐减小,因此F>Cl,所以正确顺序为F>Cl>O,C中P、As同一主族,因此P>As;D中Cl和S同一周期,因此Cl>S,S和As同一主族,因此S>As,故D正确。答案: Can you explain ____ most
deserts are located near the west coast of the continents?
A.why is it
that B.why it is
that
C.how it is
that D.how is it that