3.5 Electrons as Waves

Question 1

This scientist developed another explanation for the stability of electrons orbiting the nuclei of hydrogen atoms.

Answer 1

Louis de Brogile

Question 2

Mass of an electron

Answer 2

9.109 x 10^-31kg

Question 3

De Broglie’s Equation

Answer 3

λ = h/mu

Where h is Planck’s constant

m is the mass of the particle

u is the speed

Question 4

The wave associated with any moving particle

Answer 4

Matter Wave

Question 5

The velocity of the electron in the ground state of the hydrogen atom is 3.00×10⁶ m/s.

Answer 5

Using

λ = h/mu

6.626 x 10^-34 / (9.109 x 10^-31• 3.00x10⁶)

= 2.42 x 10^-10m

Question 6

Calculate the de Broglie wavelength of a 142g baseball thrown at 44 m/s (98 mph).

Answer 6

Remember

1J = 1kg • m²/s²

142g = 0.142 kg

= (6.626 x 10-34J)/[(0.142)•(44)] = 1.06 x 10-34m

1.06 x 10-34m

Question 7

A wave is confined to a given space, with a wavelength related to the length of space by L = n(λ/2).

Answer 7

Standing Wave

Question 8

L the context of orbitals, nodes are locations at which electron density goes to zero.

Answer 8

Nodes

Question 9

The principle that one cannot simultaneously know the exact position and the exact momentum of an electron.

Answer 9

Heisenberg uncertainty principle