NEXT Physical Change The physical properties of a

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Physical Change “The physical properties of a substance change, but the identity of the substance does not change. ” NEXT

Chemical Properties • A chemical property • 4 Examples of is any characteristic chemical properties: that gives a substance – Reacts to water the ability to undergo – Reacts to light a change that results – Reacts to oxygen in a new substance. – Flammability

Chemical Change “A change in the identity of a substance due to the chemical properties of that substance. A NEW substance or substances are formed as a result of the change. ” NEXT

Signs of a Chemical Change Bubbles Production of Heat Light Smoke Change in Color Sound NEXT

Is a chemical change reversible? • A chemical change can only be reversed by a chemical reaction, not by physical means.

Are these examples chemical or physical changes? NEXT

A Rusting Bicycle ANSWER

Melting Butter for Popcorn ANSWER

Chemical Change Oxygen in the air reacts with the metal of the bicycle. This produces a new substance called rust. NEXT

Physical Change Heating causes the butter to change from a solid to a liquid. The identity of the butter does not change. NEXT

Hammering Wood Together to Build a Birdhouse ANSWER

Physical Change Hammering the wood together causes the wood to change shape. The identity of the wood does not change. NEXT

Spoiling Food ANSWER

Chemical Change Spoiling food changes color and has a foul odor. Bacteria, mold, enzyme action, and oxidation cause spoilage. NEXT

Mixing Lemonade Powder into Water ANSWER

Physical Change After mixing the lemonade powder and water, lemonade powder and water are still present. Evaporating the water separates the ingredients. NEXT

Mowing the Lawn ANSWER

Physical Change Cutting the grass does not change the identity of the grass. NEXT

Fireworks Exploding ANSWER

Chemical Change Fireworks are composed of different metals, such as copper. After ignited, the fireworks produce light, heat, and sound. NEXT

Water Boiling ANSWER

Physical Change When water boils, water changes from a liquid to a gas. The identity of the water does not change. NEXT

Photosynthesis ANSWER

Chemical Change Plants change carbon dioxide, water, and sunlight into sugar and oxygen. New substances are formed. NEXT

Separating a Mixture of Rocks and Sand ANSWER

Physical Change Separating the rocks from the sand can be done by physical means. The identities of the rocks and sand do not change. NEXT

Adding Food Coloring to Water ANSWER

Physical Change The identities of the substances did not change. Water and food coloring are still present. NEXT

Adding Vinegar to Baking Soda ANSWER

Chemical Change Gas bubbles were produced. The baking soda and vinegar reacted to form bubbles of carbon dioxide. HOME

Can HEAT cause a chemical reaction? YES !

Can LIGHT cause a chemical reaction? YES, Photosynthesis

What is a sign of a physical change? A change in a physical property: • Shape, size, length, • change phase (solid, liquid, gas)

SIGNS OF A CHEMICAL CHANGE: • HEAT LIGHT • SMOKE BUBBLES • COLOR CHANGE • SOUND • NEW IDENTITY • CAN’T BE REVERSED BY PHYSICAL MEANS

What is…. ? A change in the identity of a substance due to the chemical properties of that substance. Chemical change

What is…. ? Any characteristic of a material that can be observed or measured without changing the identity of the material. Physical property

Any characteristic that gives a substance the ability to undergo a change that results in a new substance. Chemical Property

What is…. ? Any characteristic of a material that can be observed without changing the identity of the material. Physical Property

Examples of Physical Properties: Boiling point Melting point Volume Density Color freezing point shape length Mass

Examples of Chemical Properties: Flammability Reacts with oxygen Reacts with H 20 Ability to change with light

A ______change results in a new substance, with a new…. IDENTITY