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.
the electronegativity difference makes the bond polar and it is NOT symmetrical Br-F has two distinct ends and the F end is more negative O=C=O is symmetrical and even with polar bonds it is non polar that goes for CF4 also. was told if its symmetrical its not polar. I could understand if H-H is no polar but what about Br-F or even CH3 Are they polar or non-polar. Update: Is it right I use electronegativity by saying F is more negative so the molecule is polar..but their symmetrical. Follow.