Dry Ice - Sublimation

DON'T BE A BORON...BE DRUG FREE!

Diet Coke & Mentos

Carbon dioxide bubbles from the soda adhere to the nucleation sites (like craters on the Moon) on the mentos. This provides enough gas build-up and pressure for the explosion!

Rethink Your Drink (with 100% juice) & Snack Smart (with air-popped popcorn)!

What is the structure and function of the popcorn kernel?

What type of change does popcorn go through when it pops?

What is the molecular structure of caffeine?

How does caffeine affect your body?

SEVENTH GRADE RAISED 

$106 

FOR RELAY FOR LIFE!

Chalk & Vinegar

First, we physically crushed the chalk with the mortar and pestle to show a change in size and shape.

Next, we added the chalk to a beaker of vinegar to show a chemical change. 

Baggie Experiment

First we add the phenolphthalein to the baking soda.

We notice a chemical change in color (because it changes from white to magenta).

Next we add the calcium chloride to the phenolphthalein/baking soda mixture and we notice a chemical change in color (because it changes from pink back to white), a chemical change in temperature (because it gets really hot) and a chemical formation of gas (because the bag expands).

I forgot to record a video during class, so here's Lela doing the experiment...

Limewater & Carbon Dioxide

When you add carbon dioxide to limewater, a precipitate is formed. 

We were able to see tiny pieces of chalk floating around in the limewater.

Baking Soda & Vinegar

We know a there was formation of a gas because the balloon inflated.

We know there was a change in temperature because the beaker became really cold.

Formation of a gas and change in temperature are chemical changes.

Crushing Sugar & Melting Sugar

Crushing sugar shows a physical change - change in size and shape.

Melting sugar: we can see a gas forming from the bubbles, we can see a color change (white to yellow to brown to black), and we know there is a temperature change.

Oxygen Lab

Today we reviewed physical and chemical properties before starting our lessons on physical and chemical changes.

We know that oxygen must be present to have fire.

We were able to calculate the approximate amount of oxygen in the glass.

I forgot to take a video during class, so here's Lela doing the experiment...