SBI4U - Unit 1
Chemistry of Life Worksheet - ANSWERS
1. Match the following terms to their correct definitions:
Polar covalent
 When electrons are shared equally between
two atoms
Non-polar covalent
 When an electron is donated from one atom
and given to another, forming a bond.
Hydrogen bonding
 An atom's attraction for electrons in a bond
Ionic B
 When electrons are shared unequally between
two atoms
Electronegativity
 Water-fearing
Hydrophilic*
 Intermolecular attraction (not an actual bond)
between a H atom and an electronegative
element such as O, F or Cl
Hydrophobic
 Water-loving
* You have not seen this term yet but will learn about it pretty soon!
2. Identify the following molecules as polar or non-polar and given a reasoning
to explain your choice. If the molecule is polar, draw the arrow on the
molecule showing the direction that the electrons are being pulled. You can
also indicate which atoms are δ+ or δ-.
Polar or
Molecule
Reasoning
Non-Polar
- symmetrical & contains C/H only
- all of the H atoms have same EN
Non-Polar
and are pulling on C atom in all
directions = no EN difference
Polar
Polar
Non-Polar
- not symmetrical
- EN difference between O and C &
OH and C
- presence of O (highly EN element)
- not symmetrical (bent)
- N is more EN than C so presence
of EN difference
- charges not distributed equally
(one side is more positive and other
side is more negative)
- symmetrical from all angles
- contains C and H only
- no EN difference
(ring is made up of
C and H atoms)
Polar
Non-Polar
- not symmetrical
- Cl is highly EN, more so than C,
so presence of EN different
- this makes one side more negative
and the other side more positive =
unequal distribution of charges
- symmetrical (linear)
- no EN difference (charges
cancelled out)
- contains C & H only
- F is highly EN, more so than H so
electrons are pulled more towards H
Polar
Polar
Polar
Non-Polar
Non-Polar
- presence of O, which is a highly
EN element
- O is more EN than C = EN
difference
- this makes one side more negative
and the other side more positive =
unequal distribution of charges
- not symmetrical
- Both OH and N are highly EN =
EN difference
- this makes one side more negative
and the other side more positive =
unequal distribution of charges
- symmetrical
- contains C/H only
- all of the H atoms have same EN
and are pulling on C atom in all
directions = no EN difference
- symmetrical (linear shape)
- although O is highly EN, charges
are cancelled out as there is
another O on the other side of the
central C atom (negative charges
pull onto positive C in both
directions)