Zusammenfassung der Ressource
Chemistry (C1)
- Atoms
and
Elements
- Number of Protons =
Number of Electrons
- The Nucleus
contains Protons
and Neutrons.
- Protons are positively charged.
Neutrons have no charge.
Electrons are negatively charged.
- The Periodic Table
- Atoms are represented by symbols.
- Vertical columns are called groups.
- Elements in a group all have
the same number of
electrons in their outer shell.
- Electron Shells
- Electrons move around the Nucleus.
They occupy shells. The first shell has
a maximum of 2 electrons, whilst the
rest have a maximum of 8.
- In most atoms (other than the
Noble Gases), the outer shell isn't
full, which makes them want to
react to fill it.
- Compounds
- Atoms join
together to
make
compounds.
- A compound formed using a metal and a
non-metal are bonded using ionic bonding
as they from ions. The one that loses
becoms a positive ion. The one that gains
becomes a negative ion.
- A compound formed from non-metals consists of molecules.
Each atom shares an electron with another atom. This is
covalent bonding.
- The properties of compounds are
completely different.
- The formula shows what
atoms are in a compound.
CO2 is a compound
containing 1 Carbon atom
and 2 Oxygen atoms.