Double Slit Experiment

By: Danilo Veljovic

Waves and matter behave differently when shot through slits

Matter: Forms a vertical band dictated by the width and location of the band

Waves: form something that resembles a “secondary wave” that originates from the band

Electrons: Do something else that is very interesting

Matter being shot through a single slit

- forms a single band on the wall that that corresponds to the width of the slit

Waves being shot through a single slit

Waves radiate out as they hit the slit, with the highest amplitude right down the middle

Area with highest amplitude

Matter being shot through two slits

- forms two bands on the wall that that corresponds to the width of the slit

Waves being shot through two slits

Waves radiate out as they hit the slits, and create multiple interferences

Areas of white on the wall represent constructive intereference

Electrons being shot through one slit

Electrons form a single band when they are shot through one slit

Electrons behave like waves and therefore form bands when shot through two slits

Electrons being shot through two slits

So do electrons behave as particles or waves?

Wave-Particle Duality The concept that elementary particles

behave both as waves and as particles In this case, we observe electrons

behaving as particles through a single slit, but as waves through a double slit

A few multiple choice questions

1. When waves are fired through a single slit, where is the amplitude the highest?

• A: The amplitude is equal everywhere• B: The amplitude is highest directly in front of the slit• C: The amplitude gets higher to the sides• D: It depends on the type of wave

2. Which of the following will form multiple bands when fired through two slits

• 1: Protons• 2: Sodium ions• 3: Electrons• 4: Light rays

• A: 1• B: 1,3• C: 1,3,4,• D: 1,2,3,4

Solutions• 1: B. The amplitude is of waves fired through a single slit

is highest directly in front of the slit

• 2: C. Both protons and electrons are elementary particles and will therefore act as waves when fired through two slits. Light rays are waves and will the refore act as waves. Sodium ions are matter that is made up of many subatomic particles, and will not act as a wave.