# Quiz - Early Quantum Theory - 2 | Early Quantum Theory

1

How does the concept of quantization of energy relate to the photoelectric effect?

Energy quantization is a fundamental concept that implies electrons can only absorb or emit energy in discrete amounts or 'quanta'. In the context of the photoelectric effect, this means that only photons with energy equal to or greater than the work function can eject electrons from a metal surface. Lower energy photons, regardless of intensity, will not cause ejection of electrons.

2

What property characterizes the number of wave peaks that pass a given point per unit time?

Frequency (ν) is defined as the number of wave peaks that pass a given point per unit time. It is measured in hertz (Hz).

3

Which phenomenon was explained by Niels Bohr through his model of the hydrogen atom and how does it relate to the quantization of energy?

Niels Bohr's model of the hydrogen atom explained the observed line spectrum of hydrogen by introducing the idea of quantized energy levels. Electrons could exist only in these discrete levels, and light would be emitted or absorbed only when an electron transitioned between levels, which could explain the discrete spectral lines observed.

4

What is the range of wavelengths for infrared light within the electromagnetic spectrum?

Infrared light encompasses wavelengths ranging from 750 nm to 5 x 105 nm within the electromagnetic spectrum.

5

What is the relationship between the speed of light, wavelength, and frequency?

The speed of light (c) in a vacuum is equal to the product of the wavelength (λ) and the frequency (ν) of the light wave, as expressed by the equation c = λν.

6

What is the constant value of the speed of light in a vacuum?

The speed of light in a vacuum is approximately 2.9979 x 108 meters per second (m/s).

7

What is an electromagnetic wave?

An electromagnetic wave is characterized by oscillating electric and magnetic fields that propagate through space. These fields are mutually perpendicular and in phase, resulting in the transmission of electromagnetic energy.

8

What term describes the lowest energy level of an atom?

The ground state of an atom represents its lowest energy level, while any energy level higher than the ground state is termed an excited state.

9

What term describes the movement of electrons within an atom from one energy level to another?

Electronic transitions occur when electrons within an atom move from one energy level to another.

10

What determines the energy of orbitals in a hydrogen atom, according to Bohr's model?

According to Bohr's model, the energy of the orbitals in a hydrogen atom is determined by the principal quantum number (n).