【判断题】The two H-O bonds in a water molecule are highly polar because the O is strongly attractive for electrons, whereas the H is only weakly attractive.
【单选题】Earth: Melting in the Heat? Glaciers are melting the ice caps are disappearing into the oceans sea levels may rise by many meters as a consequence. Indigenous(本土的) Arctic peoples will find their food ...
【单选题】In formaldehyde (CH 2 =O), C is less electronegative than the oxygen to which it is bonded, and the O atom therefore owns both electrons of the C–O bond, leaving C with ___ bonding electrons.