Chapter 2 Properties of Matter. 2.1 Properties of Matter 2.1 Classifying Matter.
Ch2.1 (Properties of Matter) - Tracy Unified School District 2 notes... · Properties of matter ......
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Transcript of Ch2.1 (Properties of Matter) - Tracy Unified School District 2 notes... · Properties of matter ......
Ch 2.1 (Properties of Matter)
matter
• Anything that has mass and
takes up space is matter
http://www.chem4kids.com/files/matter_intro.html
Properties of matter
• Matter is described by two types of properties;
• 1. Physical Properties
• 2. Chemical Properties
Physical Properties—describe matter
Properties that are observed without changing the matter.
• Melting and boiling point are physical properties (the temperature at which a substance melts or boils)
• State of matter is also a physical property (solid, liquid, gas)
• Density ( a measure of how closely packed an object’s atoms are)
• http://www.harcourtschool.com/activity/hotplate/index.html
Chemical Properties
• Chemical property is the ability of matter to change into different
matter.
• Chemical changes change the chemical nature and properties of
substances to form new substances
• A match burns
• Two substances mix together turn a color different from either of them
• Toasting marshmallows
• Melt it—physical change
• Burn it—chemical change
atom
• The smallest particle that can
still be identified as the
matter it came from is an
atom
element
• Matter that is made of only
one kind of atom is an
element.
• Carbon, hydrogen, and
oxygen are all elements.
• The picture is of the element
zinc in hydrogen chloride.
Zinc + HCL
Difference between
COMPOUND & MIXTUREMIXTURE COMPOUND
1. A mixture can be separated into its particles by physical processes (filtration, evaporation, sublimation, distillation)
1. A compound cannot be separated into its constituents by physical processes. It can be separated by chemical means
2. Elements can combine in any ratio.
3. Elements do not react chemically.
4. Mixture shows the properties of its constituents
2. Elements combine in a fixed ratio.
3. Elements react chemically and make new substance.
4. A compound has new properties different from its constituents.
� CH 2.2
�(Changes in Matter)
Physical change-a change in state
• The substance is still
the same substance
• Form changes but
chemical makeup
doesn’t
Ice changes to water—
water changes to ice,
frozen water is still water
Water changes to steam, a gas, when it is heated to its boiling point,water vapor
condenses to form a liquid
Changing States of Matter-Water
• Water freezes at 0 degrees Celsius, 32 degrees Fahrenheit
• Water boils at 100 degrees Celsius, 212 degrees Fahrenheit
• http://www.chem4kids.com/files/matter_chemphys.html
Other Physical Changes
• Breaking
• Crushing
• Cutting
• Bending
• Melting
• Freezing
• Boiling
• Can happen naturally
• People can cause
changes
– Water evaporating
– Rain falling and
causing puffles
– People cause change
• Recycling paper
• Recycling metal
Chemical Properties and Changes
• Chemical changes change the chemical nature and properties of substances to form new substances
– A match burns
– Two substances mix together turn a color
different from either of them
– Toasting marshmallows
• Melt it—physical change
• Burn it—chemical change
Combustibility-a measure of how
easily a substance will burn, or
combine rapidly with oxygen
• Corrosion of metal—when iron combines with oxygen in the air, rust forms
• Gas bubbles—hydrogen peroxide on a cut
• A change in color--fireworks
Energy
• Physical and chemical changes are
accompanied by energy changes.
• energy: the capacity to do work
• work: results from a force acting on a distance
Energy Conversions
• The Law of
Conservation of
Energy states that
energy is neither
created nor destroyed.
• Energy can change
from one form to
another or transferred
from one object to
another.
Temperature and Heat
• Temperature is the measure of the thermal energy of a substance.
• The hotter an object, the greater the motion of its particles, and the greater the thermal energy.
• Heat is the transfer or exchange of thermal energy caused by a temperature difference.
Thermal Energy
• Atoms and molecules of matter are in constant, random motion, which is the source of thermal energy.
• More motion = more thermal energy.
• Is there a way to easily measure this motion?