2.9 Melting Point

Melting Point

GOALS:

^{1. Define and explain “melting point”}

^{2. Understand that different types of matter have different melting points, thus melting is a property of matter}

^{3. Understand that the melting point of matter is unaffected by sample size}

Directions

1. Take your time to complete this lesson on your first attempt.

2. Retake the Quizizz until you've earned a 💯 for the grade book 🤗 .

3. Complete the Google Form. You'll be graded for accuracy, so make sure you're ready.

🔥 YOU GOT THIS. PARTICIPATION GOAL: 💯

Melting Point Defined

The melting point of matter is "the temperature at which a solid begins to melt." The key word is "begin."

Melting Point & Temperature

Look at the photo to the right. The numbers across the bottom are a thermometer. This thermometer is measuring in degrees° Celsius. Pay attention to the thermometer as it reads the melting point temperatures of three substances to answer the question on the next slide.

Multiple Choice

According to this demonstration, what is the melting point of chocolate?

• 0° C

• 25° C

• -25° C

• 32° C

Science & Advertising

M&M's slogan for a while has been, "M&Ms melt in your mouth, not in your hand." Travel back in time to the 1980's. 😉

Multiple Choice

Suppose the temperature outside on a "hot summer's day" is greater than 25°C (which is 77°F), and you're chilling at the park. According to science, the chocolate M&Ms probably will melt in your hand. 🍫

Other Stuff Melting

Things that you wouldn't think could melt actually do. Finish watching this video to see how aluminum and even rock is melted and how high their melting points are!

Melting Point of Ice

The temperature at which a solid BEGINS melting to a liquid is called the melting point. The melting point for ice is 0°C (32°F).

Multiple Choice

What is the melting point of witches- oops, I mean ICE? 😉

• 0°C

• 32°F

• Both 0°C and 32°F

• None of these

Melting Matter

If the temperature outside is WARMER than a solid's melting point, that solid will start to MELT.

Multiple Choice

It is 42°C outside. This chocolate is clearly melting. This chocolate's melting point must therefore be 42°C or HIGHER.

• True

• False

Multiple Select

Knowing what we know about ice's melting point, when is this ice gonna melt‽ Check all that apply.

• Ms. H should have worn a helmet for this snow trust fall.

• When the sun comes out and warms us up to at least 32°F.

• It won't EVER melt. Muahaha 😈...

• Gotta be at least 50°F before it begins to melt.

Size Doesn't Matter

A single ice cube in your glass has the same melting point as the ice at the North Pole. The melting point of ANY type of matter is always the same, whether it's a lot of that matter or a little. ❄️

Multiple Choice

If I take this butter tray out of the fridge and sit it on a counter in my kitchen (room temperature), who will begin to melt first: Baby Butter or Big Butter?

• Big Butter

• Baby Butter

• They will both begin to melt at the same time/temperature.

• Neither. Ever. EVER.

Size Doesn't Matter

A smaller bag of trail mix is still trail mix. A slice of butter is still butter. A wittle twuck with a wittle wift kit is still a truck. 😉 The melting point of matter doesn't change, no matter what. That is why it is a useful property. Ice will always begin to melt at the exact same temperature.

Unique Melting Points

Every type of matter has its own melting point. Gold and silver might both be metals, but they still have different melting points. Melting point, like hardness, malleability, buoyancy, etc. is another property that helps us identify similar-looking matter.

Open Ended

The melting point of ice is 32°F. The melting point of brick is 5,072°F. All I have a blowtorch (don't ask questions, ok? 😬). How could I use it to find out if this is a blue brick house or a house made of ice?

Melting Point Test!

We can heat any solid and use instruments like a thermometer to tell us the exact temperature it begins to melt. If the house is made of ice, it will begin to melt pretty quick because fire is much hotter than 32°F. If it is made of brick, it won't melt because the temperature of a blowtorch flame is OnLy 2,610°F. 🔥

Multiple Choice

Both Yodas are about to go to the beach on another planet. If their sun is hot enough, which Yoda would begin to melt first?

• Baby Yoda

• Big Yoda

• Both will begin to melt at the same time. And we will all cry at the same time.

Multiple Choice

Both sharks are about to swim from cold water to super hot water. If the water is hot enough, which shark would begin to melt first?

• Baby Shark, doo doo do do doo.

• Big Shark

• Both will begin to melt at the same time, doo doo do do doo.

Multiple Choice

Both houses were built in northern Alaska. Fast forward 5,000 years into climate change. Which house would begin to melt first?

• The ice house, and that is exactly what's happening to Native Alaskan people 😢

• The brick house.

• Both will begin to melt at the same.

Multiple Choice

Silver and gold are two different elements, but both are metals. They have the same melting point.

• False. They are made of totally different atoms. I'm made of my mom's DNA but we have different properties (traits).

• True. Yep they're the same exact thing so they have the exact same melting point.

Multiple Select

Check all that is true about melting point.

• Every type of matter has their own unique one.

• It stays the same no matter how small the piece of matter is.

• It gives us another clue when we are trying to find out what something is.

• It is the point at which something begins to melt.

• It is a property of matter.

Google Form

Use this lesson to complete the Google form. Find the link in your Classwork or in the chat.