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Matter and Change
Chapter 1
Chemistry is a Physical
Science
●Chemistry: is the study of the
composition, structure, and properties of
matter, the processes that matter
undergoes, and the energy changes that
accompany these processes.
Matter and Its Properties
●Atom: smallest unit of an element that maintains the
chemical identity of that element.
●Mass: measure of the amount of matter.
●Matter: anything that has mass and takes up space.
●Element: a pure substance that cannot be broken
down into simpler, stable substances and is made of
one type of atom.
●Compound: substance that can be broken down into
simpler stable substances. Made from the atoms of
two or more elements that are chemically bonded.
● Mixtures are made from 2 or more
substances that retain their identities.
o Homogeneous = same throughout
oHeterogeneous = not uniform
● Pure Substance has fixed composition and
the same characteristic properties
throughout.
o Compound = 2 or more elements
chemically bonded together
o Element = identical atoms throughout.
Classification of Matter
PURE
Properties and Changes in Matter
●Extensive properties: depend on the amount of
matter that is present. (volume, mass, etc)
●Intensive properties: do not depend on the amount
of matter present. (melting point, boiling point, etc)
●Physical Property: characteristic that can be
observed or measured without changing the identity of
the substance. (melting, boiling, etc)
oPhysical Change: change that does not involve a
change in the identity of the substance. (cutting,
melting, etc)
Chemical Properties and Chemical
Changes
● Chemical properties is the substance’s ability to change
into another substance.
CO2
H 2O
(Oxygen)
● Chemical Change ( ) or Reaction is when substances are
converted into other substances
o Reactants: the ‘ingredients’ – wood, oxygen & heat
o Products: what are formed – ash, CO2 & steam
Change of state: physical change from
one state to another.
●Solid: definite volume definite shape
●Liquid: definite volume indefinite
shape
●Gas: neither definite volume nor
shape
●Plasma: high-temperature state where
most atoms lose their electrons.
Elements
● Groups/families: vertical columns
o Similar chemical properties
● Periods: horizontal rows
o Physical/chemical properties change regularly
across.
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Types of Elements
●Metals: an element that is a good
electrical conductor and heat conductor.
Properties: most are solid
at room Temperature,
malleability, ductile,
Tensile strength, luster.
●Nonmetals: poor conductors of heat and
electricity.
oMany are gases at room temperature.
Bromine is a liquid. Carbon, Phosphorous,
selenium, sulfur and iodine are solids.
oTend to be brittle.
●Metalloids: Has some characteristics
of metals and some characteristics of
nonmetals.
oSolid at room temperature, less malleable,
semiconductors, some have luster.
Which metalloid is
Essential for our
Computer-driven
Technology?
●Noble Gases: Part of the nonmetals,
these elements are gases at room
temperature.
oGenerally unreactive with other elements