Untitled Lesson

What happens when a substance is heated or cooled?

​The properties of a substance can change!

Can you think of an example of the properties of a substance changing when it is heated or cooled?

Multiple Choice

The properties of a substance can change when heated or cooled

• true

• false

Multiple Choice

What happened to the corn starch and water mixture when we added heat to it?

• it became runny and thin

• it became chunky and thick

If the substance doesn't go back to the way it was, it becomes a different substance

Multiple Choice

If you add heat to cookie dough, does it become a new substance?

• No, you can change it back to dough

• Yes! You can't change it back, it is now cookies.

Engineers must use the design cycle many times to reach their design goals.

Engineers usually also have multiple design goals.

Engineers ALWAYS follow the design cycle in order

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The Design Cycle

Multiple Choice

True or false: An engineer only has to go through the design cycle once

• true, everyone always does things correctly the first time

• false, no one ever gets it right the first time!

Multiple Choice

You can do the design cycle in any order you want!

• true

• false

If a scientist claims something to be true, they need evidence!

Not just one source of evidence too. Good scientists have multiple sources of evidence.

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Where's the evidence?

Multiple Choice

A scientist should have ________ to support logic that the evidence is accurate (or correct)

• one source

• multiple sources

​If you mix ingredients with certain properties, the mixture will take on those properties

Knowing the properties of ingredients can help us design mixtures for certain purposes.

​​Mixtures!!!

What are properties?

Properties describe something you can see, smell hear or feel about an ingredient

Think about some properties a good glue would need to have...

Multiple Choice

What is one property a good glue would need to have?

• stinky

• runny

• slimy

• strong

We love tests!!

Oh wait.. did you forget that tests are also something good scientists and engineers use when designing?

A test is when an engineer figures out what will happen in a situation.
Good engineers always make sure their tests are fair and have to run their tests multiple times.
Think about how we made out glue tests fair.

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​Tests...yay!!

Multiple Choice

Student A uses a BIG glob of glue on their sticky test.

Student B only uses a tiny bit. Will this be a fair test?

• yes, because everything is the same

• no, the different amounts of ingredients might change the strength

​A cause is one thing that makes something else happen

Cause

The result is called the effect.

Effect

Multiple Choice

If we know cinnamon has a good smell and can add flavor. What would be the effect of adding it to a mixture?

• it will make the mixture smell good

• it will make the mixture sticky

• it will make glue