Science starter Drawn an orbital diagram and give the electron configuration for N (nitrogen)

2. Determine Protons, neutrons Atomic Structure Quiz 1. Write Copper -63 in shorthand format 2. Determine Protons, neutrons And electrons for Oxygen 3. For the element magnesium (Mg) How many protons, neutrons, and electrons are there?

The Development of Atomic Models 5.1 The Development of Atomic Models Atomic models could show structure of an atom, but could not explain why atoms behaved the way that they do Ex. Change color when heated emitted light Rutherford’s model fails to explain why objects change color when heated. As the temperature of this horseshoe is increased, it first appears black, then red, then yellow, and then white. The observed behavior could be explained only if the atoms in the iron gave off light in specific amounts of energy. A better atomic model was needed to explain this observation.

SCIENCE STARTER What are three things you remember about the activity from yesterday and how it relates to electrons

Properties of atoms could be explained by the way electrons were arranged in atoms and how electrons moved in atoms

Atomic Orbital (shells) are regions of probability, where an electron Could be found Orbitals have specific shapes Based on the energy of the electrons.

Energy relates to periods 1st row (N=1) has lowest energy and 1 orbital – holds 2 electrons 2nd row (N=2) has 2 orbitals – holds 8 electrons

As electrons are excited They can move to higher energy levels. When they drop back down to their ground state a photon of light is emitted.

5.1 Atomic Orbitals Different atomic orbitals are denoted by letters. The s orbitals are spherical, and p orbitals are dumbbell-shaped. The electron clouds for the s orbital and the p orbitals are shown here.

5.1 Atomic Orbitals Four of the five d orbitals have the same shape but different orientations in space. The d orbitals are illustrated here. Four of the five d orbitals have the same shape but different orientations in space. Interpreting Diagrams How are the orientations of the dxy and dx2 – y2 orbitals similar? How are they different?

Electron Configurations 5.2 Electron Configurations The ways in which electrons are arranged in various orbitals around the nuclei of atoms are called electron configurations. Three rules—the aufbau principle, the Pauli exclusion principle, and Hund’s rule—tell you the rules that electrons follow. .

Electron Configurations 5.2 Electron Configurations Aufbau Principle According to the aufbau principle, electrons occupy the orbitals of lowest energy first. In the aufbau diagram below, each box represents an atomic orbital. This aufbau diagram shows the energy levels of the various atomic orbitals. Orbitals of greater energy are higher on the diagram. Using Tables Which is of higher energy, a 4d or a 5s orbital?

Electron Configurations 5.2 Electron Configurations Pauli Exclusion Principle According to the Pauli exclusion principle, an atomic orbital may describe at most two electrons. To occupy the same orbital, two electrons must have opposite spins; that is, the electron spins must be paired.

Electron Configurations 5.2 Electron Configurations Hund’s Rule Hund’s rule When several orbits of equal energy are available, electrons enter singly with parallel spins until all orbitals are filled. Then you may pair them up.

Electron Configurations 5.2 Electron Configurations Orbital Filling Diagram

http://www. learner. org/interactives/periodic/elementary_interactive http://www.learner.org/interactives/periodic/elementary_interactive.html

The electron configuration of an atom is a shorthand method of writing the location of electrons by sublevel. The sublevel is written followed by a superscript with the number of electrons in the sublevel. If the 2p sublevel contains 2 electrons, it is written 2p2

First, determine how many electrons are in the atom First, determine how many electrons are in the atom. Iron has 26 electrons. Arrange the energy sublevels according to increasing energy: 1s 2s 2p 3s 3p 4s 3d … Fill each sublevel with electrons until you have used all the electrons in the atom: Fe: 1s2 2s2 2p6 3s2 3p6 4s2 3d 6 The sum of the superscripts equals the atomic number of iron (26)

REVIEW What is an orbital? Where is energy the lowest? Maximum number of Electrons that the P orbital Can hold?

Electron Configurations Condensed Electron Configurations Neon completes the 2p subshell. Sodium marks the beginning of a new row. So, we write the condensed electron configuration for sodium as Na: [Ne] 3s1 [Ne] represents the electron configuration of neon. Core electrons: electrons in [Noble Gas]. Valence electrons: electrons outside of [Noble Gas].

REVIEW Using information from the periodic table 1. Draw an orbital diagram for the element Nitrogen ( N) 2. Write an electron configuration for the element iron (Fe)