Download Study Guide: Elements, Compounds, Mixtures Physical Properties

Study Guide: Elements, Compounds, Mixtures
Study Guide: Elements, Compounds, Mixtures
Physical Properties:
Can be observed or measured without chemically changing a substance.
Can be used to identify an unknown substance (some are more useful for this purpose
than others, such as: specific heat, density (mass/volume), melting point, boiling point)
Are: malleability, solubility, density, melting & boiling point, magnetism, specific heat,
color & luster, conductivity
Can be used to separate a mixture into its components
Physical Properties:
Can be observed or measured without chemically changing a substance.
Can be used to identify an unknown substance (some are more useful for this purpose
than others, such as: specific heat, density (mass/volume), melting point, boiling point)
Are: malleability, solubility, density, melting & boiling point, magnetism, specific heat,
color & luster, conductivity
Can be used to separate a mixture into its components
All matter can be classified as an element, compound or mixture.
Element:
Is made of one type of atom.
It may be a single atom, or several atoms of the same element bonded together
(Example: Fe is a single atom, O2 is two oxygen atoms bonded together….both are
elements)
Is a pure substance
Compound:
Is made of two or more different elements bonded together in a chemical reaction
(Example: H2O, NaCl)
Ionic bonds are created between metals and nonmetals, they involve a transfer
of valence electrons (Examples: NaCl, LiF)
Covalent bonds are created between nonmetals, they involve the sharing of
valence electrons. (Examples: CO2 , H2O))
Is a pure substance
Mixture:
Is the physical combination of two or more substances, the substances DO NOT
chemically react. Mixtures can be:
homogeneous (substances distributed evenly and are not distinguishable from
each other…kool aid, salt water, brass, air). Homogenous mixtures are also
called solutions
heterogeneous (substances unevenly distributed, components easily
identified……salad, soil, trail mix, blood)
Mixtures can be separated using physical processes such as distillation, filtering, sifting.
These processes take advantages of the different physical properties of the components
of the mixture.
All matter can be classified as an element, compound or mixture.
Element:
Is made of one type of atom.
It may be a single atom, or several atoms of the same element bonded together
(Example: Fe is a single atom, O2 is two oxygen atoms bonded together….both are
elements)
Is a pure substance
Compound:
Is made of two or more different elements bonded together in a chemical reaction
(Example: H2O, NaCl)
Ionic bonds are created between metals and nonmetals, they involve a transfer
of valence electrons (Examples: NaCl, LiF)
Covalent bonds are created between nonmetals, they involve the sharing of
valence electrons. (Examples: CO2 , H2O))
Is a pure substance
Mixture:
Is the physical combination of two or more substances, the substances DO NOT
chemically react. Mixtures can be:
homogeneous (substances distributed evenly and are not distinguishable from
each other…kool aid, salt water, brass, air). Homogenous mixtures are also
called solutions
heterogeneous (substances unevenly distributed, components easily
identified……salad, soil, trail mix, blood)
Mixtures can be separated using physical processes such as distillation, filtering, sifting.
These processes take advantages of the different physical properties of the components
of the mixture.
Sifting: uses size difference between components. Larger particles cannot pass through
a sifter.
Filtering: uses size differences between components as well as solubility differences.
The pores in a filter allow microscopic particles and molecules to pass through, while
larger, visible particles do not pass through.
Distillation: uses differences in boiling points. Components are evaporated and then
condensed.
Sifting: uses size difference between components. Larger particles cannot pass through
a sifter.
Filtering: uses size differences between components as well as solubility differences.
The pores in a filter allow microscopic particles and molecules to pass through, while
larger, visible particles do not pass through.
Distillation: uses differences in boiling points. Components are evaporated and then
condensed.
Pure Substances:
All particles in a pure substance are the same. Therefore, elements and compounds are
considered pure substances.
Pure Substances:
All particles in a pure substance are the same. Therefore, elements and compounds are
considered pure substances.