Chemistry Test Atomic Structure 3

Question 1

The photoelectric effect provided evidence that light behaves as:

Accepted Answer

A stream of particles called photons

Answer

Einstein explained the photoelectric effect by proposing that light consists of discrete packets of energy called photons.

Question 2

Which element has the electron configuration [Ne] 3s² 3p⁶ 3d⁵ 4s²?

Accepted Answer

Manganese (Mn)

Answer

Manganese (Mn, Z=25) has the configuration [Ar]3d⁵4s², which written without the argon abbreviation matches [Ne]3s²3p⁶3d⁵4s².

Question 3

According to Heisenberg's Uncertainty Principle, it is impossible to simultaneously know precisely the electron's:

Accepted Answer

Position and momentum

Answer

Heisenberg's Uncertainty Principle states that the more precisely position is known, the less precisely momentum (and therefore velocity) can be known.

Question 4

Which of the following ions is isoelectronic with the noble gas neon (Ne)?

Accepted Answer

Na⁺

Answer

Na⁺ loses one electron from its 11-electron neutral state, giving it 10 electrons — the same as neon.

Question 5

Which property of electrons was demonstrated by the Davisson-Germer experiment?

Accepted Answer

Wave-particle duality

Answer

The Davisson-Germer experiment showed electron diffraction, proving electrons have wave-like properties (wave-particle duality).

Chemistry Practice Test

Chemistry Practice Test

Chemistry Test Atomic Structure 3