Elements, Compounds, and Mixtures
Name ________________________________________
Science _____
Background: Matter is the material of the (1)___________________ and can be defined as anything that has mass and
takes up (2) ___________________. Most of the matter around us consists of mixtures of many (3) ________________.
Soil, air, lemonade, and wood are all mixtures. The main characteristic of a mixture is that it has a variable (4)
__________________. For example, soil is a (5) ___________________ of many substances with varying proportions,
depending on the type of soil and where it is found.
Word Bank: space
mixture
substances
soil
universe
composition
Mixtures can be classified as either (6) __________________ or homogeneous. A heterogeneous mixture is a mixture
that is not uniform in composition. If one portion of the mixture were to be sampled, its composition would be (7)
___________________ from the composition of another portion. Consider muddy water or dusty
air
which can both be classified as (8) ________________________. In these substances, particles
are dispersed throughout a fluid; these particles in suspension tend to settle out over time. A
chocolate chip cookie is a heterogeneous mixture because the number of chips (9) _______________ throughout the
cookie; every bite will have a different number of chip. Soil, containing bits of decayed material along with sand, silt,
and/or clay, is also a heterogeneous mixture. Italian salad dressing is a heterogeneous mixture.
Word Bank:
different
element
heterogeneous
suspensions varies
A homogeneous mixture, also called a solution, is a mixture that has a completely (10) ________________ composition;
it is the same throughout the solution... The components of the mixture are (11) ________________ distributed
throughout the sample. Air, salt water, and brass are examples of homogeneous mixtures, or solutions. Air is a (12)
_______________ solution consisting of a mixture of gases; salt water is a liquid solution, and (13)
____________________is a solid solution of copper and zinc. A colloid is a type of homogenous mixture that is thick
and gooey. Gels, glue and (14) __________________are examples of colloids. Mixtures, both homogeneous and
heterogeneous, can be
(15) ___________________ into pure substances by physical methods like filtration and
evaporation
brass
evenly
gaseous
Jell-O
separated uniform
A pure substance is one with a uniform and definite composition. Pure substances can be divided into two groups:
Word Bank:
elements and compounds. (16) _________________ are the simplest forms of matter, which cannot be decomposed into
simpler substances by any chemical or physical means. Elements are the building blocks for all other substances. Some
examples of elements include hydrogen, (17) _______________, carbon, and sulfur. Elements can combine with one
another to form (18) ___________________. Compounds are substances composed of two or more elements chemically
combined that can be separated into simpler substances only by (19) ___________________means. Water, for example,
is a compound because pure water is composed of only H20 molecules... Each molecule of water is a chemical
combination of two hydrogen atoms and one oxygen (20) __________________. Water can be
decomposed into its elements only by chemical means. A process called electrolysis, where an
electric current is passed through the water, is used to break it down into its component
elements, hydrogen and oxygen.
Word Bank: atom
chemical
compounds
Elements
oxygen
water
Elements, Compounds, and Mixtures
Characteristics that allow you to distinguish one kind of matter from another are called properties. A physical
property is a quality or condition of a substance that can be observed or measured without changing the identity of
the substance. Physical (21) _________________ can help to identify a substance. Some examples of physical
properties of matter are color, solubility, mass, odor, magnetism, hardness, melting point, and (22) _____________.
A chemical property is the ability of a substance to undergo chemical reactions and to form new substances.
Chemical properties can also help to identify a substance. Some examples of che mical properties of matter are the
ability to rust, corrode, decompose, or react.
Word Bank: elements properties
substances
density
Mixtures are simply a heterogeneous or homogeneous physical (23) _______________ of two or more substances.
Mixtures can be separated based solely on physical properties, or by undergoing physical changes. The melting of
ice, the freezing of water, the evaporation of water, or the bending of a piece of metal are all
(24) _________________ changes which do not change the (25) _______________ of the substance; the formula
for water is always H 20 no matter what phase the water is in. Physical separation techniques-such as filtration,
evaporation, or distillation-are ways to separate a mixture into its component parts. The properties of each
component part before mixing and after separation will not be (26) ______________ by undergoing the physical
separation. For example, imagine making a mixture of sugar in water. The sugar can be recovered by evaporation of
the water; the water can be recovered by condensation. The sugar has the same properties before mixing and after
(27) ______________. The same is true of the water.
Word Bank: changes
identity
combination
separation
altered
physical
Compounds, on the other hand, can be made or separated based on chemical properties or by undergoing chemical
changes. A chemical change, sometimes called a chemical (28) ____________________, is one in which a given
substance becomes a new substance or substances with different properties and
different composition. For example, the burning of leaves, the baking of bread and the
rusting of iron are all chemical changes in which the original substance has changed to
completely different substances with different physical and chemical properties. The
original substance cannot be recovered easily. For example, imagine burning sugar with
(29) _______________ gas. The resulting products are very different from the sugar. The combustion of sugar
results in (30) _______________________ gas and water being produced.
Word Bank: reaction
chemical
different
composition oxygen
Elements, Compounds, and Mixtures