Standard 2 LESSON 8 Chemical Reactions

Properties and Changes in Matter Matter can be described in two kids of properties: Physical properties Chemical properties Changes in matter can be described by: Physical change Chemical change

Fill in the blank Matter can be described by ________________ & _______________ properties Changes in matter can be described by ________________ & ____________ change

Properties of Matter Physical property is a characteristic of a substance that can be observed without changing the substance into another substance. Ex. Color , hardness, texture, shine, flexibility, temperature at which a solid melts Ice melts at 32 degrees F. The chemical properties do not change because water is the same substance frozen or liquid

Fill in the Blank Examples of physical properties include ______________, ____________, and _______________ Color , hardness, texture, shine, flexibility, temperature at which a solid melts

Chemical Properties Chemical properties is a characteristic of a substance that describes it’s ability to change into other substances. To observe chemical properties you must watch a substance change into another substance Ex. Burning and rusting Magnesium burns  combines with Oxygen  forms magnesium oxide

Fill in the blank Chemical properties is a trait of a substance that describes it’s ability to _______________________ _______________ & _______________ are examples of chemical properties Change into other substances Burning & rusting

Chemical Reaction Chemical Reaction: change in matter that produces one or more new substances in a chemical change Ex. Gas burns in car engine  new substances is cars exhaust Chemical change occurs when bonds break and new ones form Chemical Reaction examples: https://www.youtube.com/watch?v=FofPjj7v414

Fill in the blank A chemical Reaction is change in matter that produces ________________ in a chemical change. Ex. Gas __________ in car engine  new substances is _______________ Chemical change occurs when ___________ break and new ones form New substances, burns, car exhaust, bonds

Evidence for Chemical Reaction Changes in properties Color change A solid may appear when two solutions mix Gas may be produced (bubbles) Heat/flame produced or absorbed Changes in energy Endothermic reaction: energy is absorbed exothermic reaction: releases energy https://www.youtube.com/watch?v=JSiBSSFKRwE

Physical Change A physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. The size or shape of matter may be changed No chemical reaction occurs. Physical changes are usually reversible.

Fill in the Blank A physical change is a type of change in which the form of matter is ______________ but not _______________ The ____________ or ____________ of matter may be changed No __________________ occurs. Physical changes are usually __________________

Examples of Physical Change Crumpling a sheet or paper Breaking a pane of glass Freezing water into ice  Chopping vegetables Dissolving sugar in water (sugar mixes with water, but the molecules are not changed and may be recovered by boiling off the water)

Chemical Reactions Ticket to Leave Physical or chemical 1. Baking bread 2. Peeling an orange 3. Rotting Eggs 4. Melting Ice 5. Burning Wood 6. Fireworks 7. Wood to sawdust Chemical, 2. physical, 3. chemical, 4. physical, 5. Chemical, 6. chemical, 7. Physical