Download Modern Model of the Atom Student Notes and Assignment

Modern Model of the Atom
The most recent model of the atom is called the Quantum Mechanical Model. It was derived
from a mathematical equation used to describe the energy and location of an electron in a
hydrogen atom by the scientist, SHRODINGER.
Characteristics of the model:

the atom has no definite shape and there is no precise orbit

electrons are now thought to be located on PRINCIPAL ENERGY LEVELS which are
assigned numbers

Each energy level is divided into ENERGY SUBLEVELS

Each energy sublevel corresponds to an ATOMIC ORBITAL (often referred to as a
cloud)
An ATOMIC ORBITAL is a region in space where there is a high probability of finding an
electron.
s orbitals are sphere shaped
- always have 1
p orbitals are dumbbell shaped
- always have 3
d
- always have 5
f
complex shapes
- always have 7
The ways in which electrons are arranged around the nuclei of atoms are called ELECTRON
CONFIGURATIONS. The rules that govern the way the electrons fill the atomic orbitals are:
1. AUFBAU PRINCIPLE - electrons enter orbitals of the lowest energy levels first
2. PAULI EXCLUSION PRINCIPLE - an atomic orbital may hold at most two electrons.
Each must have an opposite spin.
3. HUND’S RULE - when electrons occupy orbitals of equal energy one electron enters each
orbital until all the orbitals contain one electron with parallel spins before filling the orbitals
with opposite spins.
Modern Model Assignment
1. List and describe the three rules that govern the way atomic orbitals are filled.
2. In 4p3
a. What does the ‘4' mean?
b. What does the ‘p’ mean?
3. Draw the diagram to show the order in which atomic orbitals were filled.
4. Draw Aufbau diagrams for:
a. nitrogen atom
b. rubidium atom
c. platinum atom
d. nickel atom
e. sulfur ion
f. iodine ion
5. Write Electron Configurations for:
a. selenium atom
b. cesium atom
c. bromine ion
d. potassium ion
6. Write Noble Gas Notation for 4a, 4b, 5a, and 5b