Chemical Change
What is one indicator of a chemical change?
Different CP, bubbles, lights, heat change, new substance is created
D = Mass/Volume
What does CER stand for?
Claim, Evidence, and Reasoning
The temperature at which a substance changes state from a liquid into a gas.
boiling point
Liquid -> Solid
Freezing
is something dissolving in water a physical change or a chemical change?
PHYSICAL
**DAILY DOUBLE**
If something has a mass of 12g and a volume of 2ml what is the density?
Density = 6
Is this a good claim?
"Yes, a chemical change has occurred because the boiling point of the substances changed in test 2"
No
The particular temperature at which a substance changes state from a solid into a liquid.
Melting Point
Energy of MOTION
Kinetic Energy
There are 2 substances, liquid A and liquid B.
Liquid A is clear, smells like flowers, and has a density of 1.4
Liquid B is clear, smells like ammonia, and has a density of 4.2.
After mixing them and heating them in a test tube, bubbles form. Then the test tube separates into two layers.
Layer 1 has a density of 2.8
Layer 2 has a density of 6.5.
Did a chemical change occur?
Yes, b/c the density changed & there were bubbles
What is the density of water?
True or False: You only need one piece of evidence to prove your point
False - You need 2-3 pieces of evidence
True or False: The size of an object can change, but its density will remain constant.
True
Which way does heat move?
High to Low
what is an example of a chemical reaction?
Candle burning, Fire, Baking, baking soda & vinegar,
What is the density of a sample with a volume of 6 cm3 and a Mass of 24 g?
4 g/cm3
After a student measures the mass and volume of two different substances, he sees that they are different and makes the following claim:
The substances are not the same because they have different mass and volume.
Is that claim correct?
NOPE b/c mass is not a CP
What is the difference between Chemical Properties and Physical Properties?
Chemical Properties = change the substance
Physical Properties = can observe without changing the substance
** DAILY DOUBLE**
Using a graduated cylinder to measure the volume of an odd-shaped object is called the...
water displacement method
Event that occurs as two or more substances are combined to form a new substance.
Chemical Reactions
The density of this concrete block is 2400 kg/m3. What is the density of HALF of this block?
2400 kg/m3
What should you include in the reasoning section of the CER?
the scientific concept that supports your evidence and backs up your claim
What are the characteristic properties of a substances
BP, MP, FP, Solubility, Flammability, Odor, Color, Corrosiveness, Density
What happens to the space between the particles when a substance heats up?
IT EXPANDS