Warm Up 1.Write the equation for the release of a beta particle by Pb Write the equation for Po-219 undergoing 1 alpha decay.

Warm Up 1.Write the equation for the release of a beta particle by Pb-211 Pb  e + Bi 2. Write the equation for Po-219 undergoing 1 alpha decay. Po  He + Pb

Electron configuration and periodic trends

- Electrons occupy orbitals around the nucleus - Electrons in a particular path have fixed energy

The energy level of an electron is the region around the nucleus where the electron is likely to be moving. Principle energy levels are assigned values in order of increasing energy n = 1, 2, 3, 4

Each energy level can be divided into sublevels Energy Level (n) # e-Sublevel n = 121s n = 282s 2p n = 3183s 3p 3d n = 4324s 4p 4d 4f

The sublevels each hold a set amount of electrons s - can hold 2 e- p - can hold 6 e- d - can hold 10 e- f - can hold 14 e-

Orbital Diagram

Order in which electrons fill the sub orbitals

This diagram represents the electron configuration for Carbon

The red arrows represent the possible locations of electrons shared with carbon when in a covalent bond.

Lets Find the Orbital Diagram for Mg s - can hold 2 e- p - can hold 6 e- d - can hold 10 e- f - can hold 14 e- Mg – Magnesium has how many total electrons? 12 Next, we set up our diagram:

Lets Find the Orbital Diagram for Mg s - can hold 2 e- p - can hold 6 e- d - can hold 10 e- f - can hold 14 e- Mg – Magnesium has how many total electrons? 12 Next, we set up our diagram:

Lets Find the Orbital Diagram for Mg Mg 1s 2 2s 2 2p 6 3s 2 s - can hold 2 e- p - can hold 6 e- d - can hold 10 e- f - can hold 14 e-

Review: What is a valence electron? How many valence electrons are found in Oxygen?

Periodic Trends Atomic Size Ionization energy Electronegativity

Atomic Size (Radius) Increases down a group Decreases left to right

Atomic Size (Radius) Increases down a group Decreases left to right

Atomic Size (Radius) Increases down a group Decreases left to right

Ionization Energy The energy required to overcome the attraction of the nuclear charge and remove an electron from a gaseous atom – Increases left to right across a period – Decreases down a group

What do you notice about the elements at the peaks and valleys?

Electronegativity The tendency for the atoms of an element to attract electrons when they are chemically combined with atoms of another element – Increases left to right across a period – Decreases going down a group

Let’s practice!!!