Zusammenfassung der Ressource
Atomic Structure and the Periodic Table
- Atoms
- All substances are made
from atoms
- They're really small
- Nucleus
- In the middle of an atom
- Contains proton and
neutrons
- Positive charge because
of protons
- Whole mass of atoms
concentrated in nucleus
- Electrons
- Move around the nucleus
in electron shells
- Negatively charged.
- No mass
- Neutral - have no
charge overall
- Same number of electrons and protons
- Charge of proton and
electron cancel each other
out
- Elements
- A substance made up of
atoms that all have the
same number of
protons in their nucleus
- Atoms can have different
number of protons, neutrons
and electrons. Its the number of
protons which decides the kind
of atom it is.
- Atoms of each
element can be
written by a letter or
two
- Isotopes
- Have different number
neutrons
- Different forms of
the same element
- Same atomic number,
different mass number
- Compounds
- Elements react together
and the atoms form a
compound
- Substances formed
from two or more
elements
- Atoms are in fixed
proportions throughout
the compound - held
together by chemical
bonds
- Making bonds
involves atoms
giving away,
taking or
sharing
electrons
- Compound consisting
of metal and
non-metal
- Metal atom loses
electrons to form
positive ions
- Non-metal atoms gain
electrons to form
positive ions
- Opposite charges of ions
means they are strongly
attracted to each other -
ionic bonding
- A compound made from
non-metals consists of
molecules
- Each atoms shares an
electron with another
atom - this is
covalent bonding