Matter Mysteries
True or false: If you cannot see matter, it no longer exists.
Which is an observation: “The liquid is blue” or “The liquid is dangerous”?
“The liquid is blue.”
What are the physical properties of matter?
Possible answers:Color, texture, odor, conductivity of heat, conductivity of electricity, magnetism, floats or sinks in water, solubility, boiling point, and melting point.
Melting butter: physical or chemical change?
Physical Change
Which tool would you use to measure mass?
A balance or digital scale.
Why can an open container appear to lose mass during a reaction?
Gas or other matter can leave the system.
What is an inference?
A reasonable explanation or conclusion based on observations and evidence.
What is matter?
Anything that has mass and takes up space.
Rust forming on a nail: physical or chemical change?
Chemical Change
Which tool would you use to measure liquid volume?
A graduated cylinder or measuring container.
What is the difference between an open system and a closed system?
Matter can enter or leave an open system. In a closed system, matter is contained.
A student says, “The ground is wet, so it must have rained.” What part is the observation and what part is the inference?
Observation: the ground is wet. Inference: it rained.
Name the three common states of matter.
Solid, liquid, and gas.
Ripping paper changes its size and shape. What kind of change is this?
Physical Change
A graduated cylinder reads 42 mL before an object is added and 57 mL after. What is the object’s volume?
15 mL
A sealed bag has a mass of 150 g before a reaction and 150 g after. What does that show?
Matter was conserved; the total amount of matter stayed the same.
Why should scientists repeat measurements or trials?
To improve reliability, check for patterns, and reduce the effect of mistakes or unusual results.
Which is NOT matter: water vapor, light, oxygen gas, or a pencil?
light
Name two clues that may suggest a chemical change.
Possible answers: gas production, unexpected color change, temperature/energy change, formation of a new solid, light.
Why is it important to include units when recording measurements?
Units tell what the number means and allow measurements to be understood and compared correctly.
A reaction in an open cup goes from 200 g to 196 g. A sealed version stays at 200 g. What is the best explanation?
About 4 g of matter likely left the open system, probably as gas. Matter was not destroyed.
A student’s results do not match the prediction. Should the student change the data? What should the student do instead?
No. Record the actual data, analyze what happened, consider errors, and revise the explanation or test again.
A balloon is inflated. What evidence could you use to prove the air inside is matter?
Use a balance to determine if it has mass and it takes up space.
A candle is melting and burning at the same time. Identify the physical change and the chemical change.
Melting candle = physical change
Burning candle = chemical change
An electric circuit in which the devices are connected in one continuous loop.
What is a series circuit?