Comparing Physical and Chemical Properties

The video explores the continuous changes in the world through chemical and physical processes. Chemical changes involve the formation of new substances with different properties, such as rusting and combustion. Physical changes alter the form or phase of a substance without changing its chemical identity, like water freezing or melting. The video also discusses how these changes often occur together, as seen in the rock cycle and processes like decomposition and digestion. Examples include candle burning, where both physical and chemical changes are evident.

What happens during a chemical change?

• The substance changes its shape.

• New substances with new chemical properties are formed.

• The substance changes its phase.

• The substance remains the same.

Which of the following is an example of a chemical change?

• Boiling water

• Rusting of iron

• Cutting paper

• Melting ice

What is a physical change?

• A change that does not alter the chemical properties of a substance.

• A change that involves combustion.

• A change that alters the chemical properties of a substance.

• A change that produces new substances.

Which of the following is an example of a phase change?

• Breaking a rock

• Grinding coffee beans

• Cutting a piece of wood

• Water vapor rising from a lake

What happens when wax melts?

• It changes from a liquid to a solid.

• It changes from a solid to a liquid.

• It changes from a gas to a liquid.

• It changes from a liquid to a gas.

What are igneous rocks?

• Rocks formed from organic material.

• Rocks formed when melted rock cools and solidifies.

• Rocks formed from extreme pressure.

• Rocks formed from sediment layers.

How are sedimentary rocks formed?

• By cooling of melted rock.

• By extreme pressure and heat.

• By the melting of existing rocks.

• By the cementation of smaller rock pieces.

What is an example of a metamorphic rock?

• Limestone

• Marble

• Sandstone

• Granite

What process reduces dead leaves to compost?

• Combustion

• Condensation

• Decomposition

• Evaporation

What occurs during the digestion of food?

• Only physical changes

• Both physical and chemical changes

• Only chemical changes

• No changes