The Melting Point of Substances — Reading Comprehension

Grades

Standards

5-PS1
MS-PS1-4
RI.6.3
RI.7.1

About This Reader

This middle school science reading passage, titled 'The Melting Point of Substances', explores the physical property known as melting point—the temperature at which a solid becomes a liquid. Students learn that the melting point is unique for each substance, such as ice melting at 0°C. The passage clearly explains that melting is a physical change, meaning the substance remains the same even as its state changes. This aligns with the NGSS standard MS-PS1-4, which focuses on changes in particle motion, temperature, and the state of matter. Real-world examples, including melting ice, butter, and metals, help connect the concept to everyday life. Students are introduced to the idea that heating causes particles to move faster and spread apart, leading to a change in state. The passage includes eight multiple choice questions to check for understanding, vocabulary, and the main idea. It also supports Common Core reading standards like RI.6.1 and RI.6.4. With accessible language and a Flesch Reading Ease score around 70, this is an ideal cross-curricular resource that blends literacy with physical science.

CONTENT PREVIEW

Have you ever left an ice cube on the kitchen counter? After a few minutes, it begins to turn into water. This process is called melting, and it happens when a solid changes into a liquid. The temperature at which this change occurs is called the melting point.

Each substance has its own melting point. For example, the melting point of ice (solid water) is 0 degrees Celsius. That means ice begins to melt at this temperature and becomes liquid water. Metals, wax, and even chocolate all have their own melting points too.

Melting point is considered a physical property. A physical property is something you can observe or measure without changing the substance into something new. When ice melts, it becomes water, but it’s still H₂O. The substance hasn’t changed—only its state has. That’s why melting point is useful for identifying different materials.

Understanding the melting point helps scientists and engineers. For example, in factories, knowing when metal will melt is important when building machines or tools. In cooking, knowing the melting point of ingredients like butter or chocolate helps control texture and flavor.

Melting also helps us learn how particles behave. When a solid heats up and begins to melt, its particles start to move faster and spread out, turning into a liquid. This shows how temperature affects the state and motion of particles in a substance.

In summary, the melting point is the temperature at which a solid becomes a liquid. It is a physical property that helps us understand and identify materials in everyday life and science.

Fun Fact: Gallium is a metal that melts in your hand! Its melting point is only about 29.8°C (85.6°F)—just a little warmer than room temperature.

What is the melting point?

The point where liquid turns into gasThe point where solid turns into gasThe temperature at which a solid becomes a liquidThe speed at which something cools down

What is the melting point of ice?

100 degrees Celsius0 degrees Celsius-10 degrees Celsius10 degrees Celsius

Why is melting point considered a physical property?

Because it changes the substance into a new oneBecause it only applies to waterBecause it changes the shape of the objectBecause it doesn't change the substance's identity

What happens to particles when something melts?

They stop movingThey move slowerThey move faster and spread outThey freeze in place

Which of the following is an example of melting?

Water turning into steamIce turning into waterButter getting coldMetal rusting

What is the main idea of this passage?

How ice freezes into waterWhy solids are hardThe melting point and its role as a physical propertyCooking techniques for melting chocolate

Why is it helpful to know the melting point of a substance?

To break down objectsTo cook fasterTo identify and work with materialsTo create cold environments

Which word best describes the term melting?

CoolingHeating until a solid becomes liquidFreezingMixing