5.1 Light, speed, wavelength, and frequency of light and Bohr model

Explain the difference between a continuous spectrum and an atomic emission spectrum.

A continuous spectrum is exactly what is says it is, a continuous range of electromagnetic frequencies that go from radio waves at very low frequencies, up to gamma rays and x-rays at very high frequencies. An atomic emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted by the element's atoms or the compound's molecules when they are returned to a lower energy state. Each element's emission spectrum is unique.

What is a quantum of energy?

A quantum is the minimum quantity of energy that can either be lost or gained by an atom by only a discrete value.

Where are electrons located according to the Bohr model?

According to the Bohr model, a planetary model, the electrons encircle the nucleus of the atom in specific allowable paths called orbits. The electron is not allowed to occupy any of the spaces in between the orbits.

What is the speed of all forms of electromagnetic radiations?

All electromagnetic radiation moves through a vacuum at a constant speed of 2.998 × 10⁸ m/s. While the presence of air molecules slows the speed of light by a very small amount, it is still equal to 3.00 × 10⁸ m/s when rounded to three significant figures, so this is the value that we will use.

Use the Bohr model to explain how the atomic emission spectrum of hydrogen is produced.

An emission line is produced by an atom in a ``excited'' energy state---the electron is not in as low an energy orbit as possible. In order to go to a lower energy orbit, the electron must lose energy of a certain specific amount. The atom releases the energy is the form of a photon with that particular energy. The energy of photon = the difference in energy of the energy orbits (energy ladder rungs).

Explain how the stacking of poker chips is related to quantum theory.

Because you can only increase or decrease the height based on the poker chip, assuming that all chips have a uniform size, you can't make the poker chips thinner, so the stack is only increased or decreased based on the discrete unit of the chip

Know the equation energy as it relates to Planck's constant and photon frequency E=hν

E=hν Energy = Planck's constant * photon frequency (ν)

List five examples of electromagnetic radiation.

Electromagnetic radiation is a form of energy that exhibits wavelike behavior as it moves through space. Examples are: radio waves, microwaves, infrared light, visible light, ultra violet, x-rays, and gamma rays.

What SI unit is Energy measured in?

Joule. a joule is equal to 1 kg·m²/s²

What is Planck's constant?

The Planck constant links the amount of energy a photon carries with the frequency of its electromagnetic wave. It is s about 6.62606×10⁻³⁴ J·s

How are the energy and frequency of light related?

The greater the energy, the larger the frequency and the shorter (smaller) the wavelength

How are the energy and wavelength of light related?

The greater the energy, the larger the frequency and the shorter (smaller) the wavelength.

How are the wavelength and frequency of light related?

The greater the energy, the larger the frequency and the shorter (smaller) the wavelength.

What is the threshold frequency?

The minimum frequency needed to cause the ejection of electrons is referred to as the threshold frequency.

Why does the photoelectric effect support the idea that light can behave as a particle?

The photoelectric effect is a phenomenon that occurs when light shined onto a metal surface and causes the ejection of electrons from that metal. It was observed that only certain frequencies of light are able to cause the ejection of electrons. If the frequency of the incident light is too low, like red light, then no electrons were ejected even if the intensity of the light was very high or it was shone onto the surface for a long time. If the frequency of the light was higher, like green light, then electrons were able to be ejected from the metal surface even if the intensity of the light was very low or it was shone for only a short time. This minimum frequency needed to cause the ejection of electrons is referred to as the threshold frequency. In 1905, Einstein realized that light was behaving as if it was composed of tiny particles (photons) and that the energy of each particle was proportional to the frequency of the electromagnetic radiation that it was a part of.

What is the photoelectric effect?

The photoelectric effect is a phenomenon that occurs when light shined onto a metal surface causes the ejection of electrons from that metal.

What SI unit is frequency (ν), represented by

Typically, frequency is measured in units of cycles per second or waves per second. One wave per second is also called a Hertz (Hz), which can be expressed in SI base units as a reciprocal second (s⁻¹).

List the colors of the visible spectrum in order from shortest to longest wavelength.

Violet light has the shortest wavelength and the highest frequency while Red light has the longest wavelength and the lowest frequency. VIB G YOR from shortest to longest ROY G BIV longest to shortest. Overall, visible light ranges in wavelength from about 400 - 700 nm and has frequencies in the range of 1014 Hz

What happens when a hydrogen atom absorbs a quantum of energy? Use the terms ground state and excited state in your answer.

When a ground-state electron of hydrogen absorbs a quantum of energy it is raised (excited) to a higher energy level.

Know the equation to determine speed of light as a reference to wavelength and photon frequency c=λν ,

c=λν , The speed of light (c) = wavelength (λ) * photon frequency (v)

Light can be treated as particles called photons. The energy of a photon depends on the light's frequency when treated as a wave. What are the two equations that relate wavelength to frequency and to energy?

c=λν and E=hν

Arrange them in order of increasing wavelength the electromagnetic spectrum: (i) x-ray, (ii) infrared, (iii) microwave, (iv) visible, (v) radio wave, (vi) gamma ray, (vii) ultraviolet.

gamma ray, x-ray, ultraviolet, visible, infrared, microwave, radio

Arrange them in order of increasing energy the following regions of the electromagnetic spectrum: (i) x-ray, (ii) infrared, (iii) microwave, (iv) visible, (v) radio wave, (vi) gamma ray, (vii) ultraviolet.

radio, microwave, infared, visible, ultraviolet, x ray, gamma ray.

What SI unit is wavelength measured in

wavelengths are often measured in meters, centimeters, or nanometers (1 m = 10⁻⁹ nm)