This is because butterfly caterpillars are host specific. Plant-wise, the caterpillars of some butterfly species like asters, black-eyed Susan, clover, lupines, milkweed, sedum or violets. Aspen, birch, cherry, hackberry, oak or willow trees make caterpillars of other butterfly species equally happy.
each Br-F bond would be polar or BF4-, there is an extra electron making this a polar molecule. PCl5 has the Cl atoms that must be as far apart from each other as possible and therefore would create equal but opposite pulls.ach Br-F bond would be polar or BF4-, there is an extra electron making this a polar molecule. PCl5 has the Cl atoms that must be as far apart from each other as possible and therefore would create equal but opposite pulls.
If the pull from each of the bonds cancels each other out, like forces that are equal in magnitude but opposite in direction, the molecule will be nonpolar. Examples of this are BeCl 2, AlCl 3 and CF 4. Although the bonds are polar, the entire molecule does not have one side that is more or less negative than another.The molecule is nonpolar and so they have little attraction to each other. If the pull from the polar bonds in a molecule do not cancel each other out, the molecule is polar.Examples are NaCl, H 2 O, and NH 3. The shape of the molecule makes one side of it more negative than another-the molecule is polar. Polar molecules do attract each other.e can think of ionic bonds as being the most polar a bond can be. There is nothing more polar than the ends being different by a whole, complete electrical charge. If a molecule is made of polar bonds, it may be polar or nonpolar.