The Atom and Electromagnetic Radiation

You are watching: A substance made up of only one kind of atom

Fundapsychological Subatomic Particles Electromagnetic Radiation
Light and also Other Forms of Electromagnetic Radiation

Pwrite-up Symbol Charge Mass
electron e- -1 0.0005486 amu
proton p+ +1 1.007276 amu
neutron no 0 1.008665 amu

The variety of proloads, neutrons, and also electrons in an atom can be determined from a collection of easy rules.

The number of protons in the nucleus of the atom is equal to the atomic number (Z). The variety of electrons in a neutral atom is equal to the number of proloads. The mass number of the atom (M) is equal to the amount of the variety of prolots and also neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

Examples: Let"s recognize the number of protons, neutrons, and also electrons in the adhering to isotopes.

12C 13C 14C 14N

The different isotopes of an aspect are determined by composing the mass number of the atom in the top left corner of the symbol for the facet. 12C, 13C, and 14C are isotopes of carbon (Z = 6) and therefore contain 6 protons. If the atoms are neutral, they likewise need to contain 6 electrons. The only distinction in between these isotopes is the variety of neutrons in the nucleus.

12C: 6 electrons, 6 proloads, and 6 neutrons

13C: 6 electrons, 6 protons, and also 7 neutrons

14C: 6 electrons, 6 prolots, and 8 neutrons

Practice Problem 1:

Calculate the variety of electrons in the Cl- and also Fe3+ ions.

Click right here to check your answer to Practice Problem 1

Electromagnetic Radiation

Much of what is known about the framework of the electrons in an atom has been obtained by researching the interactivity between matter and also different creates of electromagnetic radiation. Electromagnetic radiation has some of the properties of both a pwrite-up and a wave.

Particles have actually a definite mass and also they occupy room. Waves have actually no mass and also yet they carry energy as they take a trip through area. In addition to their ability to lug energy, waves have actually 4 other characteristic properties: rate, frequency, wavelength, and amplitude. The frequency (v) is the number of waves (or cycles) per unit of time. The frequency of a wave is reported in systems of cycles per second (s-1) or hertz (Hz).

The idealized illustration of a wave in the figure below illustprices the meanings of amplitude and also wavelength. The wavelength (l) is the smallest distance between repeating points on the wave. The amplitude of the wave is the distance in between the greatest (or lowest) suggest on the wave and the facility of gravity of the wave.


If we meacertain the frequency (v) of a wave in cycles per second and the wavesize (l) in meters, the product of these two numbers has the units of meters per second. The product of the frequency (v) times the wavelength (l) of a wave is therefore the speed (s) at which the wave travels via area.

vl = s

Practice Problem 2:

What is the rate of a wave that has a wavesize of 1 meter and a frequency of 60 cycles per second?

Click below to examine your answer to Practice Problem 2

Practice Problem 3:

Orchestras in the USA tune their instruments to an "A" that has actually a frequency of 440 cycles per second, or 440 Hz. If the rate of sound is 1116 feet per second, what is the wavesize of this note?

Click right here to inspect your answer to Practice Problem 3

Click below to see a solution to Practice Problem 3

See more: Fix: Chrome Continue Where You Left Off Not Working, How To Fix Chrome Continue Where You Left Off

Light and also Other Forms of Electromagnetic Radiation

Light is a wave through both electrical and also magnetic components. It is therefore a kind of electromagnetic radiation.

Visible light contains the narrow band of frequencies and wavelengths in the percentage of the electro-magnetic spectrum that our eyes can detect. It consists of radiation via wavelengths in between around 400 nm (violet) and 700 nm (red). Since it is a wave, light is bent once it enters a glass prism. When white light is concentrated on a prism, the light rays of different wavelengths are bent by differing quantities and also the light is transformed into a spectrum of colors. Starting from the side of the spectrum where the light is bent by the smallest angle, the colors are red, oarray, yellow, green, blue, and also violet.

As we deserve to watch from the complying with diagram, the energy carried by light increases as we go from red to blue across the visible spectrum.


Due to the fact that the wavesize of electromagnetic radiation have the right to be as lengthy as 40 m or as brief as 10-5 nm, the visible spectrum is just a tiny percent of the complete array of electromagnetic radiation.


The electromagnetic spectrum has radio and TV waves, microwaves, infrared, visible light, ultraviolet, x-rays, g-rays, and cosmic rays, as shown in the figure over. These different creates of radiation all travel at the rate of light (c). They differ, but, in their frequencies and also wavelengths. The product of the frequency times the wavelength of electromagnetic radiation is constantly equal to the rate of light.

vl = c

As a result, electromagnetic radiation that has actually a long wavelength has actually a low frequency, and radiation via a high frequency has a brief wavesize.

Practice Problem 4:

Calculate the frequency of red light that has a wavesize of 700.0 nm if the rate of light is 2.998 x 108 m/s.