Physical and Chemical Changes

Physical Changes No new substance is formed Indicators: size and shape change, phase change, mixture, dissolving

Chemical Changes New substance formed from original substances that lose their original properties Hydrogen is a flammable gas that combines with…

Oxygen to produce… A gas that is essential for life and for combustion to occur.

the compound water which is a colorless liquid that is not flammable and doesn’t support combustion

Indicators of a chemical change: Produce gas Produce heat and light

More indicators of a chemical change include Burning Producing a solid Temperature change Oxidation Odor Oxidation Rusting

and also a color change may indicate a chemical change

Physical or Chemical Get ready to decide if the following examples are chemical changes or physical changes.

Example 1- chemical or physical change? Raindrops become snowflakes

Example 2-Apple starts to turn brown Chemical or Physical Change?

Example 3- Chemical or Physical Change? Alkaseltzer tablet in water

Example 4-Bicycle rusts

Example 5- Butter melts –Chemical or Physical?

Example 6-Chemical or Physical Acid on limestone White Cliffs of Dover chalk

Example 7-Chemical or Physical Change? Cream is whipped

Example 8-Chemical or Physical Change? Dynamite Explodes

Example 9-Chemical or Physical Change? Cell phone battery

Example 10-Chemical or Physical Change? Lemonade powder is mixed into water

Answers 1-Physical-Raindrops become water. Substance is still water. Went through phase change of liquid to solid 2-Chemical-Apple turns brown is evidence of a color change 3-Chemical-Alkaseltzer in water produces a gas called carbon dioxide. There is also a temp. change 4-Chemical-Bicycle rusting is oxidation because the metal united with oxygen in the air.

More Answers 5-Physical-Butter melting is a phase change from a solid butter pat to a liquid. 6-Chemical-Acid on limestone produces a gas 7-Physical-Cream is whipped. This is a mixture of air and cream. 8-Chemical-dynamite explodes and produces heat and light. 9-Chemical-Cell phone battery produces heat and light 10-Physical-Lemonade powder mixes and dissolves in water.

Girls Only- Guess These Chemical or Physical 1. Fireworks explode 2.Grass is mowed 3.Hair is bleached 4.Iron gets magnetized 5.Ice cream melts

Boys Only-Guess These Chemical or Physical change? 1.Jello hardens in the fridge 2.Your lunch digests 3.Lightening bug glows 4.Log decomposes 5.Pine bark is made into mulch

Who was the best?

Answers Girls 1-C 2-P 3-C 4-P 5-P Boys 1.-P 2.-C 3.-C 4.-C 5.-P

The End