Physical Changes – Mixing & Separating (S5P1.a)
You mix sand and iron filings. Explain how you would separate them and why your method works.
What is using a magnet because iron is magnetic and sand is not?
Water changes from ice to liquid. Use particle movement to explain why this happens.
What is particles move faster as temperature increases, causing ice to melt?
A material changes color and releases gas when mixed. Explain how this evidence supports a chemical change.
What is these observations show a new substance formed?
A student mixes salt with water and later recovers the salt. Describe the investigation steps and identify the physical property used.
What is evaporating the water because water changes state and salt does not?
A student claims water boiling is a chemical change. Construct an argument using observations and particle motion to disagree.
What is boiling is a physical change because particles move faster but remain water?
Design an investigation to test whether heating sugar causes a chemical change. Identify what evidence you would look for.
What is observing color change, odor, or new substances forming?
Two students disagree about whether mixing flour and water is a physical change. Use evidence from the materials to support the correct claim.
What is it is a physical change because no new substance forms and the materials can be separated?
Explain why water vapor forms faster on a hot day than a cold day using temperature and unseen particles.
What is higher temperature causes particles to move faster and escape into the air?
A student says that a temperature change alone proves that a chemical reaction occurred. Use evidence to support or refute this claim.
What is temperature change alone does not prove a chemical change without new substances?
Design an investigation to determine whether mixing oil and water creates a new substance. Include what you would observe.
What is planning to mix them and observe that they separate into layers, showing no new substance formed?
Two identical cups of water are placed in different temperatures. Predict which will change state first and justify your reasoning.
What is the warmer cup because increased temperature increases particle motion?
During an investigation, bubbles form and the mixture smells different. Explain why this is chemical evidence and not physical.
What is gas production and odor indicate a new substance formed?
A mixture contains sand, salt, iron filings, and water. Design a multi-step investigation to separate all materials. Explain why each step works.
First use a magnet to remove iron filings. Next filter the sand from the saltwater. Then evaporate the water to recover the salt. Each step works because it uses different physical properties such as magnetism, particle size, and state change.
A sealed container of water is placed in a freezer. Later, it is moved to a warm room. Explain what happens to the water particles during both temperature changes and how this supports the idea that no chemical change occurred.
In the freezer, particles slow down and move closer together, forming ice. In the warm room, particles speed up and spread apart. The particles remain water the entire time, showing only physical changes occurred.
A student heats a substance and observes a temperature increase, bubbling, and a color change. Analyze the evidence and determine whether a chemical change occurred. Justify your claim.
A chemical change likely occurred because bubbling (gas production) and color change are evidence that a new substance formed, not just a change in temperature.