Download CHEMISTRY VOCABULARY

CHEMISTRY VOCABULARY
An ATOM is the smallest part of an element.
ELEMENTS cannot be broken down by either physical or chemical methods.
In PHYSICAL processes no new substance is made.
In CHEMICAL processes something new is made.
ATOMS have a nucleus, which contains protons and neutrons, Electrons are
arranged around the nucleus in shells or energy levels.
All atoms of the same element contain the same number of protons, they
have the same ATOMIC NUMBER.
The ATOMIC MASS or MASS NUMBER of an atom is the number of protons
plus the number of neutrons.
ISOTOPES are atoms with the same atomic number but different mass
numbers, they have different numbers of neutrons.
MOLECULES contain two or more atoms chemically joined.
COMPOUNDS contain two or more DIFFERENT atoms chemically joined.
MIXTURES can contain atoms, molecules or compounds or any combination.
Mixtures can be separated by physical processes such as
Separating mixtures (PHYSICAL METHODS nothing new made)
FILTRATION separates an insoluble solid
EVAPORATION and CRYSTALIZATION separates a soluble solid.
DISTILLATION separates a liquid.
FRACTIONAL DISTILLATION separates a mixture of liquids.
CHROMATOGRAPHY separates coloured mixtures.
METALS AND NON METALS
Metals are solids (except Mercury), high melting and boiling, shiny, malleable
(sheets) and ductile (wires) and good conductors of heat and electricity
because they have the same structure of closely packed atoms with FREE
ELECTRONS.
Most non metals are gases (H2 N2 O2 F2 Cl2) or low melting solids (S,P, I2).
They are brittle and poor conductors because they have molecular structures
and NO free electrons. A few odd ones like CARBON have giant (macro)
molecular structures like diamond. Carbon also has the graphite
macromolecular structure which has free electrons and can conduct
electricity.
METAL OXIDES ARE BASES, NON METAL OXIDES ARE ACIDS in water.
CHEMISTRY VOCABULARY 2
COMPOUNDS
IONS are charged atoms formed by loss or gain of electrons.
IONIC COMPOUNDS are formed between metals and non metals. The
metals lose electrons and non metals gain them to get full shells.
COVALENT COMPOUNDS are formed between non metals, bonds contain
shared pairs of electrons.
If you know something about SALT (sodium chloride) you know something
about IONIC COMPOUNDS
IONIC COMPOUNDS are like salt, crystalline solids, with high melting and
boiling points, they are usually soluble in water, if they contain a transition
metal they are coloured.
They are ELECTROLYTES when melted or in solution because they have
FREE IONS. (There is an enormous chemical industry based on the
electrolysis of salt.)
ELECTROLYSIS is a CHEMICAL CHANGE because new substances are
made, it only occurs when ions are free to move i.e. when molten or when
dissolved in water, NOT when solid.
If you know something about WATER and METHANE (gas) you know
something about COVALENT COMPOUNDS.
COVALENT COMPOUNDS are liquids, gases or low melting point solids, they
are not soluble in water and sometimes they react with water. They are mostly
colourless and non electrolytes because they have no ions.