**Question 1:**

### Which scientist proposed that electrons have both particle-like and wave-like properties?

Explanation: The correct answer is D) Louis de Broglie. In his doctoral thesis in 1924, Louis de Broglie proposed that electrons, as well as other particles, have both particle-like and wave-like properties. This idea, known as matter wave or de Broglie wave, laid the foundation for the wave-particle duality of matter.

**Question 2:**

### What is the wavelength of an electron with a momentum of 5 x 10^-24 kg·m/s?

Explanation: The correct answer is C) 4 x 10^(-10) m. The wavelength of an electron can be calculated using the de Broglie wavelength formula: λ = h / p, where λ is the wavelength, h is the Planck's constant (approximately 6.63 x 10^(-34) J·s), and p is the momentum. Plugging in the values, we get λ = (6.63 x 10^(-34) J·s) / (5 x 10^(-24) kg·m/s) ≈ 4 x 10^(-10) m.

**Question 3:**

### The phenomenon where electrons are confined to specific energy levels in an atom is known as:

Explanation: The correct answer is D) Electron quantization. Electron quantization refers to the phenomenon where electrons in an atom are confined to specific energy levels or orbitals. These energy levels are quantized, meaning that only certain discrete values of energy are allowed for the electrons, as described by quantum mechanics.

**Question 4:**

### Which experiment provided direct evidence for the wave-like behavior of electrons?

Explanation: The correct answer is D) Davisson-Germer experiment. In 1927, Clinton Davisson and Lester Germer conducted the Davisson-Germer experiment, which demonstrated the wave-like behavior of electrons. They observed diffraction patterns when electrons were scattered from a crystal surface, providing direct evidence of electron waves.

**Question 5:**

### The probability of finding an electron in a specific region around the nucleus is described by:

Explanation: The correct answer is A) Schrödinger equation. The Schrödinger equation, developed by Erwin Schrödinger, is a fundamental equation in quantum mechanics that describesthe wave-like behavior of particles, including electrons. By solving the Schrödinger equation for a given system, one can obtain a wave function that provides information about the probability distribution of finding the electron in different regions around the nucleus.

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