Grade: Grade 2 Subject: Science Unit: States of Matter SAT: ProblemSolving+DataAnalysis ACT: Science

Solids and Liquids

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Everything around us is made of matter! Matter comes in different forms called states. Let us learn about two important states: solids and liquids!

What Is Matter?

Matter is anything that takes up space and has weight. Everything you can touch is made of matter!

Matter comes in three main states: solid, liquid, and gas.

What Is a Solid?

A solid is matter that has its own shape. You can hold it in your hand!

Solids do NOT change shape on their own. A book stays shaped like a book!

Examples: rocks, books, pencils, ice cubes, tables, toys

Properties of Solids

  • Has a definite shape - keeps the same shape
  • Has a definite size - takes up the same amount of space
  • Can be held - you can pick it up
  • Does not flow - it stays in place

What Is a Liquid?

A liquid is matter that flows and takes the shape of its container.

Pour water into a cup, and it becomes cup-shaped. Pour it into a bowl, and it becomes bowl-shaped!

Examples: water, milk, juice, oil, honey, shampoo

Properties of Liquids

  • No definite shape - takes the shape of its container
  • Has a definite amount - takes up the same amount of space
  • Flows - moves and pours
  • Cannot be held in your hand - it runs through your fingers!

Comparing Solids and Liquids

Solid Liquid
Has its own shape Takes container's shape
Can be held Cannot be held
Does not flow Flows and pours

Worked Examples

Example 1: Identifying a Solid

Problem: Is a wooden block a solid or liquid?

Step 1: Does it have its own shape? Yes, it is shaped like a block.

Step 2: Can you hold it? Yes!

Step 3: Does it flow? No, it stays in place.

Answer: Solid - A wooden block is a solid because it keeps its shape.

Example 2: Identifying a Liquid

Problem: Is orange juice a solid or liquid?

Step 1: Does it have its own shape? No, it takes the shape of the glass.

Step 2: Can you hold it in your hand? No, it would run through your fingers!

Step 3: Does it flow? Yes, you can pour it.

Answer: Liquid - Orange juice is a liquid because it flows and takes the shape of its container.

Example 3: Same Amount, Different Shape

Problem: You pour a cup of water into a flat plate. Is there more, less, or the same amount of water?

Think: Did you add or take away any water? No!

Answer: It is the same amount. The water looks different because it spread out on the plate, but no water was added or removed.

Example 4: A Tricky One - Ice

Problem: Is an ice cube a solid or liquid?

Think: Can you hold an ice cube? Yes! Does it keep its shape? Yes!

Answer: Solid! An ice cube is frozen water. It is a solid because it has its own shape and does not flow. When ice melts, it becomes liquid water.

Example 5: Sorting Objects

Problem: Sort these: apple, milk, crayon, syrup

Solids: apple, crayon - They have their own shape and can be held.

Liquids: milk, syrup - They flow and take the shape of their container.

Practice Problems

Practice identifying solids and liquids!

Problem 1: Is a pencil a solid or liquid?

Show Answer

Solid - A pencil has its own shape and can be held.

Problem 2: Is water a solid or liquid?

Show Answer

Liquid - Water flows and takes the shape of its container.

Problem 3: Can you hold a liquid in your bare hands?

Show Answer

No - Liquids flow through your fingers. You need a container!

Problem 4: Name three solids in your classroom.

Show Answer

Examples: desk, chair, book, pencil, eraser, whiteboard, clock, backpack

Problem 5: Name three liquids you might drink.

Show Answer

Examples: water, milk, juice, lemonade, hot chocolate

Problem 6: A toy car is put in a box. Does it change shape?

Show Answer

No - Solids keep their own shape, no matter what container they are in.

Problem 7: Honey moves very slowly. Is it a solid or liquid?

Show Answer

Liquid - Even though honey is thick and slow, it still flows and takes the shape of its container.

Problem 8: What happens when you pour juice from a bottle into a glass?

Show Answer

The juice changes shape to fit the glass. It was bottle-shaped, now it is glass-shaped!

Problem 9: Is a marble a solid or liquid?

Show Answer

Solid - A marble has its own round shape and does not flow.

Problem 10: What is one way solids and liquids are alike?

Show Answer

Both take up space and have weight. Both are matter!

Check Your Understanding

Question 1: What is the difference between a solid and a liquid?

Show Answer

A solid has its own shape and does not flow. A liquid takes the shape of its container and can flow and be poured.

Question 2: What is matter?

Show Answer

Matter is anything that takes up space and has weight. Everything you can touch is made of matter - solids, liquids, and gases!

Question 3: If you pour water from a tall thin glass into a short wide bowl, does the amount of water change?

Show Answer

No! The amount of water stays the same. Only the shape changes because water takes the shape of whatever container it is in.

Question 4: Why can you hold a rock but not hold water?

Show Answer

A rock is a solid with a definite shape - it does not flow. Water is a liquid that flows and will run through your fingers because it has no definite shape.

Next Steps

  • Explore: Find 5 solids and 5 liquids at home
  • Experiment: Pour water into different shaped containers
  • Next Lesson: Learn about gases - the third state of matter!
  • Challenge: What happens when ice melts?