Date: October 16, 2015
Aim #16: What are some of the unique properties of
water?
Do Now: Warm-Up Notebook
Date
10/16
Title of Activity
Chemical Bonding
Page #
31
HW:
1) Worksheet- Properties of Water DUE TUESDAY
2) Guided Reading 2-2 DUE THURSDAY
3) Quiz (Inorganic Chemistry)- Wednesday 10/21
& Thursday 10/22 (day of double period)
Aim #16: What are some of the
unique properties of water?
Water is a Polar Molecule
What does that mean?
A molecule in which opposite ends have
opposite electrical charges
This is due the unequal sharing of electrons between
the hydrogen and oxygen atoms
Why is there unequal sharing of
electrons in water molecules?
The nucleus of Oxygen has 8 protons which pulls
the electrons farther from the hydrogen nucleus
which only has 1 proton
Is H2 a polar molecule?
No, because each of the hydrogen electrons are
being pulled from an equal amount of protons.
H2 is an example of a Non-Polar Molecule
Water molecules attract each other
in a specific way due to this
unequal sharing
The slightly negative oxygen atom of one molecule
attracts the slightly positive hydrogen atom of
adjacent water molecules
This attraction between water
molecules is called Hydrogen
Bonding
Hydrogen Bonding is responsible for water’s
unique properties
Unique Property #1
The molecules of water in ice are less densely
packed than those of liquid water
Therefore, ice floats in water
Unique Property #2
Cohesion- the tendency of
molecules of the same kind
to stick to one another
Adhesion- the attraction
between unlike molecules
Trees depend on these
properties of water to help
transport water from their
roots to their leaves
This is known as Transpiration
Water is able to move
against the force of
gravity
Water from the leaves
evaporate and water is
Pulled through the vessels
In the tree from the roots
What is Surface Tension?
Cohesion pulls the molecules at the surface tightly
together and a filmlike boundary is formed
Unique Property #3
Why does water take longer to heat up in the
summer and longer to cool in the winter?
H bonds make water more resistant to temperature
change
Unique Property #4
Water has a great ability
to dissolve other
substances
What is a solution?
Solution- is a uniform
mixture of two or more
substances
Solvent- the substance
that dissolves
the other substance
Solute- the substance that is
dissolved
**When water is the solvent, the result is called an
Aqueous solution