Physical or Chemical?
An ice cube melts into liquid water. What type of change happened?
Physical change
Name ONE piece of evidence that may show a chemical change occurred.
Color change, temperature change, OR formation of gas
What unit did we use to measure temperature?
Degrees Celsius (°C)
What four materials did we use in our experiment?
Water, dish soap, baking soda, and vinegar
What substance did Joules and Bunsen need aboard the spacecraft?
Oxygen
A change happens, but no new substance is formed. What type of change is it?
Physical change
A mixture suddenly starts producing bubbles. What evidence might this show?
Formation of gas
What tool did we use to measure temperature?
Thermometer
What happened to the temperature during our reaction?
It decreased/got colder.
Did Test #1 produce the oxygen they needed?
No
Vinegar and baking soda react and produce new substances. What type of change occurred?
Chemical change
A mixture starts at 22°C and ends at 15°C. What evidence of chemical change did you observe?
A temperature change
If a reaction takes in energy and the temperature decreases, what is it called?
Endothermic
What gas did our reaction produce?
Carbon dioxide (CO₂)
What gas did Test #1 produce?
Carbon dioxide (CO₂)
A piece of paper is cut into smaller pieces. Did a new substance form?
No, it's a physical change.
Name all THREE pieces of evidence we looked for today.
Change of color, change of temperature, formation of gas
If a reaction releases energy and the temperature increases, what is it called?
Exothermic
Was Test #1 endothermic or exothermic?
Endothermic
What gas was produced during the elephant toothpaste reaction?
Oxygen (O₂)
What is the MOST important difference between a physical and chemical change?
A chemical change forms a new substance. A physical change does not.
Which one is NOT a chemical change: rusting metal, burning wood, or melting ice?
Melting ice. It is a physical change.
One reaction gets colder and another gets hotter. Can BOTH still be chemical changes?
Yes. Chemical reactions can have different energy changes.
Give TWO pieces of evidence from our experiment that support the claim that a chemical change occurred.
Formation of Gas and Temperature Change
Is the elephant toothpaste reaction endothermic or exothermic?
Exothermic. It releases energy and the temperature increases.