Chapter 1 Notes
Chemistry: Matter
and Change
Chemistry
Science dealing with the structure, properties
and behavior of all substances that make up
the universe.
– Examples: elements; compounds; chemical
reactions; nuclear reactions; color; phase changes;
Six Areas of Chemistry
•
•
•
•
•
Organic – carbon containing
Inorganic – non-organic
Biochemistry – chemistry in living things
Analytical – ID of composition of materials
Physical – properties/changes of matter and
energy associated
• Theoretical – mathematical perspective of the
behavior of chemical compounds
Matter
• Anything that has mass and takes up space.
• Matter can be solid, liquid, gas or plasma.
• It cannot be created or destroyed (in normal
chemical reactions). However, it can change
forms.
Law of Conservation of Mass (also
called Conservation of Matter and
Conservation of Energy)
• In a normal chemical reaction, matter cannot
be created or destroyed.
Mass
• A measure of the amount of matter in an
“object”
• Units: g, mg, kg
States of Matter
• Solids – definite shape, definite volume
• Liquids – no definite shape, definite volume
• Gases – no definite shape, no definite volume
• Gases vs Vapors
– Gases are typically in the gaseous phase at room
temperature.
• Examples: oxygen, carbon dioxide
– Vapors are substances that are typically in the
solid or liquid phase at room temperature.
• Examples: perfume, acetone, water, alcohol
Phase changes
• As temperature changes, as well as pressure,
substances can change phases.
• Phase changes can be from solid  liquid
 gas or even solid  gas.
• Melting/Freezing
– Occurs when a substance changes from solid 
liquid.
– Melting of ice and freezing of water both occur at
0ºC.
• Boiling/Condensing
– occurs when a substance changes from liquid 
gas.
– Water boils at 100ºC. Steam condenses at 100ºC.
• Sublimation
– occurs when a substance changes directly from
solid to gas.
– Dry ice (solid CO2) and iodine sublime.
Properties of Matter
• Describe the composition, structure and
behavior of a substance.
– Examples: color, mass, boiling pt., flammability,
taste
Quantitative vs. Qualitative
Properties
• Quantitative – a property that uses
measurement
– Examples: mass, temperature, melting point
• Qualitative – a property that can be expressed
without measurement
– Examples: color, smell, flammability, reactivity
with water
Extensive vs. Intensive Properties
• Extensive – depend on the amount of matter
present
– Examples: mass, volume, length
• Intensive – not dependent on the amount of
matter present
– Examples: temperature, density, boiling point,
electrical conductivity
Physical vs. Chemical Properties
• Physical properties – observable with the senses
and can be determined without destroying the
object.
– Examples: color, shape, mass, length, density, specific
heat, odor
• Chemical properties – indicates how something
reacts (or doesn’t) with something else.
– Examples: the ability of iron to rust; the flammability
of rubbing alcohol
Physical Change vs. Chemical Change
• Physical change – a change in matter that
does not involve a change in the composition
of individual substances.
– A physical change does not produce a new
substance.
– Examples: ripping paper, melting ice, crushing
potato chips, dissolving salt, evaporation
• Chemical change – a change in matter that
does involve a change in the composition of a
substance.
– A chemical change always produces a new
substance.
– Examples: burning paper, rusting metal, decaying
of a dead mouse
Indicators/Signs of a Chemical
Change/Reaction
1)
2)
3)
4)
5)
Color change
Precipitate formed (solid formed)
Gas produced (bubbles)
Odor change (smells different)
Energy change (gains or loses heat – feels
warmer or cooler)
Energy/Heat Change
• Exothermic
– Heat is lost; energy is given off; it feels warmer.
– Examples: hand warmer, charcoal burning, dilution of
acids
• Endothermic
– Heat is gained; energy is taken in; it feels cooler
– Example: chemical ice pack
• There can be an energy/heat change
(endothermic or exothermic) even if there is not
a chemical change
Classification of Matter
Pure Substance
• Matter with the same composition
throughout. It can be an element or a
compound.
Mixture
• A combination of two or more substances in
which each substance keeps its unique set of
properties. It can be separated into two or more
pure substances.
Pure substance
• Elements
– Simplest form of matter that cannot be broken
down in smaller substances.
– Elements are represented by symbols from the
periodic table.
– Examples: iron (Fe), hydrogen (H), silver (Ag),
potassium (K)
• http://periodictable.com/
Pure substance
• Compounds
– Chemical combination of two or more elements
joined together in a fixed proportion.
– Compounds are represented by a formula – a
combination of chemical symbols showing an
exact ratio of elements.
– Examples: calcium chloride (CaCl2), sodium
bicarbonate (NaHCO3), butane (C4H10), water
(H2O)
Mixtures
• Heterogeneous mixture
– A mixture that has multiple phases.
– Individual substances can clearly be “seen” in the
mixture and are not uniformly distributed.
– Examples: trail mix, oil and vinegar salad dressing,
concrete, a glass of Dr. Pepper with ice
Mixtures
• Homogeneous mixture
– A mixture that has one phase; substances are
evenly distributed.
– There is a constant composition throughout.
– Examples: Kool-Aid, air, stainless steel
Homogeneous mixtures are also known as
solutions.
• Solutions consist of solute and solvent.
• Solute – the substance being dissolved.
• Solvent – the substance that dissolves the
solute.
– Example: Salt water is a solution. Salt is the
solute. Water is the solvent.
Alloy
• A solid solution usually made up of two or
more metals.
• Examples: stainless steel, brass, bronze
HW: 4, 7, 9, 11, 12, 16, 17,
18, 19, 21, 23, 24, 27, 29
(pp. 23-24)
• due Fri., 8/30
Periodic Table of Elements
The periodic table is organized into periods,
groups and families based on properties.
• Periods
– horizontal rows
– there are 7 periods numbered from top to bottom
(1-7)
– each period represents a new energy level
Periodic Table of Elements
• Groups
– vertical columns
– there are 18 groups numbered from left to right
(1-18)
– they are sometimes called families
– elements within groups have similar properties
Metals, Nonmetals, and Metalloids
• Metals
– left of the stair-step
– conduct heat and electricity well
– high luster/shiny (often gray or white, but can be
yellow or brown)
– malleable (can be bent or hammered)
– ductile (can be drawn out into a long thin wire)
– generally solids at room temperature (Hg is a
liquid)
Metals, Nonmetals, and Metalloids
• Nonmetals
– right of the stair-step
– do not conduct heat and electricity well
– lack luster
– brittle
– many are gases at room temperature (some are
solids, Br is a liquid)
Metals, Nonmetals, and Metalloids
• Metalloids
– along the stair-step
– B, Si, Ge, As, Sb, Te
– have properties of both metals and nonmetals
– some are semiconductors
• they conduct electricity better than nonmetals but not
as well as metals
• conductivity can be improved by doping – adding
another element