Química

Mixtures, compounds and
elements

October 17th, 2011

Matter can be classified into

Matter

Pure matter

Element

Mixture

Compound

Homogeneous
mixture

Heterogeneous
mixture

Mixture
Consist of two or more different elements
and/or compounds - physically
intermingled.
Their parts can be separated into their
constituent parts by physical means (e.g.
distilation ofliquids or separating magnetic
and non-magnetic solids using a magnet),
and have many of the properties of their
constituent parts

Mixtures
All substances can be divided into two
categories:
Homogeneous
Heterogeneus
Heterogeneous substances are multi-phases
substances, it means they have more than
one phase

Mixtures

Homogeneous
(only one phase)

Pure subtances
(constant(constant composition)

Homogeneous mixtures
(variable
(variable composition)

One type of atom present
(Fe, Ca)

More than 1 type of atom
(H2O)

Heterogeneous
(more than one phase)

Mechanical mixtures
(variable
(variable composition)

Solution
A solution is a homogeneous mixture of a
solute dissolved in a solvent (eg; salt or sugar
in water.)
Solute: A solute is a solidthat can dissolve in
a solvent. For example, salt is a solute which
can dissolve in water.
Solvent: A solvent is a liquid, which can
dissolve a solute. For example, sugar can
dissolve in water.

Percentage composition in mass
Percentage of the component=

mass1(g)
(100)
mass1(g) + mass2(g) + mass n(g)

Chocolate milk
Water 500 g
Chocolate 25 g
Sugar 15 g

Water 240g
Powder 50g
Sugar 15 g
Percentage of each compound
Powder 16.39%
Water 78.69%
Sugar= 4.92%

Mixtures cannot be separated by
chemical methods.
Separating mixtures through Physical Methods
Distillation: Is a process that separates a
mixture based on boiling points of the
mixture’s components.
Centrifugation: Separates mixtures by the
densities of the components.
Magnetic: Can be used toseparate a mixture
of elements iron and aluminium.
Evaporation: By boiling point.
Filtering:The filter traps the solid part.

Chemistry

October 18th 2011

Element
Consist of only one type of atom
Robert Boyle Proposes a definition of
Element
Element (1660)
Element as a fundamental substance that
cannot be broken down further by chemical
means.

Compound
A compound is a puresubstance that consists of
two or more elements chemically combined in a fixed
proportion, that can be further subdivided into simpler
substances by chemical (not physical) means only
like
like sodium chloride.
(NaCl)
A molecule is the smallest part of a compound
whose properties are those of the compound.
A compound can be represented by using a
chemical formula.

Chemical representationof elements,
molecules, atoms, ions and isotopes
Atom The smallest indivisible particle of matter that
can have an independent existence. Atoms are the
smallest particle into which an element can be
divided.
Atomic number The number of protons in the
nucleus of an atom.
Atomic weight The sum of the weights of an atom's
protons and neutrons, the atomic weight differs
between isotopes ofthe same element.

Matter Anything that has mass and occupies space.
Element A substance composed of atoms with the
same atomic number; cannot be broken down in
ordinary chemical reactions.
Isotopes Atoms with the same atomic number but
different numbers of neutrons; indicated by adding
the mass number to the element's name, e.g., carbon
12 or 12C.
Nucleus is the small, dense, positivelycharged
center of the atom. Contains most of the atom’s
mass.

Neutron Are particles in the nucleus of an
atom that have no charge
Electron A negatively charged particles
found in electron clouds outside the nucleus.
The size of the electron clouds determines
the size of the atom.
Proton Are positively charged particles in the
nucleus of an atom.

Mass number: protons+ neutrons...