Slides in this set
Elements and the periodic table
· Dimetri Mendeleev
· An element only contains one type of atom e.g.
· Periodic table is a list of all the elements found so
far they are ordered by their atomic number e.g.
Potassium's atomic number is 19
· ROWS = PERIODS
· COLUMNS = GROUPS
· First group are known as `alkali metals'…read more
· Each element has a symbol e.g. Potassium's
symbol is a `K'
· In the middle of the atom there is a nucleus.
This contains protons and neutrons. Outside
of the nucleus are electrons.
· Electrons are arranged around the nucleus in
energy levels called shells.
· The way the electrons are arranged in these
shell is called electronic configuration.…read more
· Two or more atoms make a molecule.
· Atoms are held together by shared pairs of
electrons, called a covalent bond.
· Two or more different atoms make a compound.
· When a non-metal and a metal react (e.g.
magnesium + oxygen = magnesium oxide) they are
called ions, not atoms.
· Metal ions have a positive charge, and non-metal
ions have a negative charge. These two charges
hold the compound together.
· This is called an ionic bond.…read more