5.2 QUANTUM THEORY AND THE ATOMPART 2

The quantum mechanical model of the atom

We left off with Bohr’s model of the atom. What did it do for us? What did it not do?

The quantum mechanical model of the atom successfully describes

electrons in all elements, both conceptually and mathematically

Like Bohr’s model, electrons can only exist ____________________ however- there are differences…

1. In quantum mechanics, electrons are treated as _________________ (Bohr treated them as ___________________)

De Broglie’s idea was that if light can have both wave and particle characteristics –

_________________(Note: this actually explains Bohr’s idea that electrons can only exist in certain energy levels.)

2. Also, you can never know exactly where an electron is… you can only predict the probability of it being found in a certain area of space. Why is this so?

This is called the

The Principle states:The more you know about an electron’s _______and ________, the less you know about its___________, and vice versa

Experimental evidence for the Principle

Heisenberg was driving down the road, and was stopped by a police officer.“Sir,” says the officer, “do you know how fast you were going?!” Heisenberg says “no , but I know...”( finish his sentence)

Schrodinger developed the

These mathematically describe the electron as a wave, and they work for all elements

To review: The quantum mechanical model of the atom includes ideas from:

*note: other scientists also contributed

SCIENTIST HIS CONTRIBUTION

BOHR

DE BROGLIE

HEISENBERG

SCHRODINGER

How is the quantum mechanical model of the atom going to help us this year in our quest to understand

how things happen in our world?

We will use the solutions to the Schrodinger wave equations which involve

quantum numbers. Quantum numbers describe electrons, and

areas where electrons may be found/how the

electrons are arranged around the nucleus. In other words, from quantum numbers we can

derive electron configurations

Why are electron configurations important?

Remember – chemistry is based on electrons and how they are arranged; so determining electron configurations is the first step in explaining how

chemistry – and the world - work!