INVESTIGATION 3: AIR IS MATTER

Learning GOAL In Air Is Matter you will learn that the gas produced in the reaction is carbon dioxide, one of many gases in air.

OBJECTIVES Students Will: Investigate air to confirm that it qualifies as matter – –it has mass and occupies space. Use syringes to discover that air can be forced into a smaller space (compressed) or larger space (expanded). Develop explanations for their observations, starting to develop a particulate model for matter.

OBJECTIVES Content. Gas is matterit has mass and occupies space. Content. Gas compresses when force is applied; gas expands when force is withdrawn. Investigate. Use syringes to observe the effects of pressure on gases. Explain. Use drawings and words to explain gas compression and expansion. Explain. Explain the composition of gas in terms of individual particles in constant motion.

AIR IS MATTER Whats in the Bubbles? Think about the chemical reaction between sodium bicarbonate and citric acid. What happened? We studied the periodic table of elements and became familiar with the elements from which all matter is made. The gas that formed must be made from the elements present in the reactants. What could the gas be?

Whats in the Bubbles? Open your lab packet to page 24, Whats in the Bubbles? You will have 6 minutes to work with your face partner to answer the questions. Timer

Elements are in the Bubbles? What elements could be in the gas bubbles? –Na –H–H –C–C –O–O What gas might be in the bubbles? –hydrogen (H) –oxygen (O) –carbon dioxide (CO 2 ) The gas formed in the reaction between sodium bicarbonate and citric acid is carbon dioxide and the chemical formula is CO 2.

Carbon Dioxide CO 2 The carbon dioxide we produced in our reaction bottles is just one of a large number of gases. Where is carbon dioxide found? Where would you go to find some CO 2 in the natural world? CO 2 is a product of combustion and cellular respiration. CO 2 generated by these and other processes ends up in the air. CO 2 is a natural part of Earths atmosphere.

What is Air? Working with your group, discuss what air is. 3 minutes3 minutes Appoint a reporter to take notes as the group talks. Each group will share ideas about what air is. Transparency no. 5 Properties of Gas Properties of Gas How can you demonstrate that gas is matter?

Air Has Matter Ponder….. –This ball is hollow like a basketball or soccer ball. –It has air in it. –The ball and air together make a ball system. –I also have an inflation pin. –Is there any way I can find out if the air in the ball has mass?

Demonstration Time Mass before inflation _______. Mass after inflation _________. Questions to ponder? –Did the mass of the ball system change? –Did the mass of the rubber in the ball change? –What caused the mass of the ball system to change? –Does air have mass? –Did air take up space in the ball? How do you know?

QUESTIONS?????