Question

properties of water

1. in the box to the right, draw two water molecules

hydrogen bonded to one another.
label:
a) the symbol for all elements
b) the negative and positive charges on all 6
elements
c) the hydrogen bonds.

1. in the following chart, fill in the missing property, definition, or example.

property definition example
cohesion
water sticks to other substances

Explanation:

Step1: Draw H₂O molecules

Each water molecule is $\ce{H2O}$, with an oxygen atom covalently bonded to two hydrogen atoms.

Step2: Add partial charges

Oxygen has a partial negative charge ($\delta^-$), each hydrogen has a partial positive charge ($\delta^+$).

Step3: Draw hydrogen bond

The $\delta^+$ H of one $\ce{H2O}$ bonds to the $\delta^-$ O of another; label this bond.

Step4: Define cohesion

Cohesion = water sticks to identical water molecules.

Step5: Give cohesion example

Example: Surface tension (water forming droplets).

Step6: Identify adhesion

"Water sticks to other substance" = adhesion property.

Step7: Give adhesion example

Example: Water climbing a paper towel.

Answer:

1. (Diagram description):

• Two $\ce{H2O}$ molecules: each has a central oxygen (O) atom connected to two smaller hydrogen (H) atoms.
• Label O with $\delta^-$, each H with $\delta^+$.
• Draw a dashed line between the $\delta^+$ H of one molecule and the $\delta^-$ O of the other; label this line "Hydrogen bond".

1. Completed chart:

Property	Definition	Example
Adhesion	Water sticks to other substance	Water rising up the fibers of a paper towel