Quiz on the 1st 10 elements on the periodic table!!! Quiz Today Quiz on the 1st 10 elements on the periodic table!!!

Niel’s Bohr In Bohr’s model electrons move around the nucleus like planets around the sun Bohr was correct to assign energy levels to electrons, but they do not have a planetary orbit Instead electrons are found in the electron cloud

Electron Clouds The electron cloud is not a path that the electron follows but rather an idea of probability At the denser (darker) parts of the cloud is where electrons are MOST likely to be found The electron cloud is a representation of the orbitals around a particular atom

Valence Electrons Atoms may give/take/share e-’s Closer to nucleus = higher energy e- Tend to fill lowest levels first Levels hold specific number of e-’s Innermost = 2 Second = 8 Third = 18 Fourth = 32

Valence Electrons (cont.) Outermost level = valence e-’s Valence e-’s allow atoms to interact and form bonds Number of valence e-’s determines the atom’s behavior Elements with the same number of valence e-’s have the same behavior Elements with full outer shells do not react

Electron Configuration Energy levels have different types of orbitals in them S-orbitals hold 2 electrons P-orbitals hold 6 electrons D-orbitals hold 10 electrons

Electron Configuration Rules The row equals the energy level. Exception: The “D” orbital is 1 less energy level than the row its on. Read left to right, top to bottom. If an orbital is full, you simply write it as full and do not include its constituent parts

Sodium – Na Magnesium – Mg Aluminum –Al Silicon – Si Phosphorus – P Sulfur – S Chlorine – Cl Argon – Ar Potassium – K Calcium - Ca