CHEMISTRY 3

• Rutherford model- atom is a miniature solar system with the electrons moving like planets around nucleus
• borh model- quantized the orbits in order to explain the stability of the atom
• s orbital- electrons with no angular momentum occupy region of space like this
• schrodinger model- abandoned the idea of precised orbits, replacing them with a description of the orbitals where electrons were most likely to be found
• electron configuration- arrangement of an atom's electron with respect to its nucleus
• elements that don't have noble gas try to attain such a configuration by entering into chemical reactions
• stable molecules- formed when atoms combine so as to have outer shells holding 8 electrons
• ionic model- electrons are transferred from one atom to another to achieve noble gas

  configuration.
• The atom giving up the electrons become positively charge (cation),
• the atom accepting the electrons becomes negatively charged (Anion).
• Ionic bonds are formed when

  elements in Group IA to IIA (except hydrogen) combines with elements in group VIA to VIIA
• When sharing of available outer elements of the atoms occur, a covalent bond is formed.
• There is no

  electron transfer in covalent bonding.
• All chemical reactions involve the breakage and

  reformation of chemical bonds of molecules to form different substances.
• The reactants (the substances that are combined to

  react with one another) appear on the left side of the equation,
• the products (substances produced by the

  reaction) are written on the right side of the equation.
• Composition Reaction (synthesis or combination reaction) is a type of chemical reaction where a more

  complex substance is broken down into two or more simpler substances.
• Decomposition Reaction is a type of chemical reaction where a more complex substance is broken

  down into two or more simpler substances.
• Single Replacement Reaction is a type of chemical reaction in which a less reactive element is

  displaced from a compound by a more reactive element.
• Double Displacement reaction is a type of reaction wherein cations of two compounds switch anions

  to form new products.