Pick Up an Ice Cube with a String

Pour salt over ice cube and string

Pour salt over ice cube and string

Materials
Full cup of water
Ice cube
Salt
~12 inches of string

Procedure
Put your ice cube in your cup of water.
Drape your piece of string across the ice cube; make sure there are a few inches of slack on each side.
Pour salt on top of the ice cube and string.
Wait for 60 seconds, then, taking the ends of the string in each hand, slowly lift the ice cube out of the water.

Results

Carefully lift ice cube

Carefully lift ice cube

You’ve picked up an ice cube using just a piece of string! How? According to explorable.com, the addition of the salt disrupts the state of equilibrium that existed between the ice cube and the water. The salt molecules begin to dissolve and mix with the water molecules; this changes the water’s rate of freezing. The rate of melting is now far quicker than the rate of freezing, causing the ice to melt rapidly. In order to restore the state of equilibrium, the water’s freezing point drops, causing the ice to freeze. The salt begins crystallizing and the ice ultimately refreezes around the string.

How Salt Melts Ice

Materials & Equipment:

Water, salt, 2 pie pans, a freezer

Procedure:

Setup

Setup

Fill each pan with water to about 2/3’s capacity. Place the pans on your freezer shelf, then wait for the water to freeze. After the water has turned to ice, set your pans side by side, and choose one to sprinkle with sea salt.

Results:

The salted ice will begin melting immediately. This is very similar to the way that our cities brine roads in anticipation of a snow or ice event. The science behind this method? Salt lowers the freezing (and also melting) point of water; therefore, the outside temperature must decrease significantly in order to maintain the salted ice.

Results - Salted Ice

Results – Salted Ice

Results - No Salt Added

Results – No Salt Added

Waiting for the Snow to Start? Make a Snow Measuring Stick!

Decorated Measuring Stick

Decorated Measuring Stick

Materials:
Paint stir stick
Ruler
Marker
Assorted Decorations (paint, foam shapes, pipe cleaners, etc)

Procedure:

Paint your stir stick, if desired (we used white paint for our snowman).

Create a base line a couple of inches above the bottom of the stir stick to mark zero inches. From there, use your ruler to mark off each inch going toward the top of the stir stick.

Decorate your measuring stick as desired.

Once your measuring stick finishes drying, find a nice open spot that will receive the most snow. Press your measuring stick in the ground up to your base line.

Snow Stick in the Ground

Snow Stick in the Ground

Results:
As the snow falls, periodically check on your measuring stick. We’d love to see how much it snows in your area, so please take pictures and share on the Greensboro Science Center’s Facebook page: https://www.facebook.com/GreensboroScienceCenter!

Erin with Snow Stick

Erin with Snow Stick