The ester methyl butyrate has two electrophilic carbons. Using the letter labels, identify these carbons, then check your answer. H3C-CH2-CH2-COO-CH3

a b c d e

The most electrophilic carbon is:

The other electrophilic carbon is:

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

Particle exchange energy though elastic collision , hope this .

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.