1. 12.10 The Wave Motion of Matter & Quantum Mechanics Since light behaves as waves and particles, Louis de Broglie, questioned whether particles matter behaved as waves. Since light behaves as waves and particles, Louis de Broglie, questioned whether particles matter behaved as waves. De Broglie derived an equation that describes the wavelength (λ) of a moving particle: De Broglie derived an equation that describes the wavelength (λ) of a moving particle: λ = λ = h ___ mv

2. 12.10 The Wave Motion of Matter & Quantum Mechanics De Broglie’s equation predicts that all matter exhibits wavelike motions. De Broglie’s equation predicts that all matter exhibits wavelike motions. It set the stage for an entirely new method of describing the motions of subatomic particles, atoms, and molecules It set the stage for an entirely new method of describing the motions of subatomic particles, atoms, and molecules

3. 12.10 The Wave Motion of Matter & Quantum Mechanics Mechanics (classical and quantum) is the study of the motion of bodies Mechanics (classical and quantum) is the study of the motion of bodies Classical mechanics adequately describes the motions of bodies much larger than the atoms of which they are composed. It appears that such a body gains or loses energy in any amount. Classical mechanics adequately describes the motions of bodies much larger than the atoms of which they are composed. It appears that such a body gains or loses energy in any amount. Quantum mechanics describes the motions of subatomic particles and atoms as waves. These particles gain or lose energy in packages called quanta. Quantum mechanics describes the motions of subatomic particles and atoms as waves. These particles gain or lose energy in packages called quanta.

4. 12.10 The Wave Motion of Matter & Quantum Mechanics Another feature of quantum mechanics that is not present is classical mechanics is the uncertainty principle derived by German physicist Werner Heisenberg. Another feature of quantum mechanics that is not present is classical mechanics is the uncertainty principle derived by German physicist Werner Heisenberg. The Heisenberg uncertainty principle states that it is impossible to know exactly both the velocity and the position of a particle at the same time. The Heisenberg uncertainty principle states that it is impossible to know exactly both the velocity and the position of a particle at the same time. There is an inverse relationship between knowing the position and the velocity of a particle. There is an inverse relationship between knowing the position and the velocity of a particle.