How many electrons would it take to equal the mass of a helium nucleus? How can I draw Bohr diagrams? How do protons determine the properties of an atom? How many neutrons can an atom have?
What is the atomic structure of carbon? Why is the number of protons and electrons equal in an atom? Question 2b These different kinds of the same element are called isotopes. Isotopes are atoms that have the same atomic number and are therefore of the same element but different mass numbers.
The composition of atoms of the naturally occurring isotopes of carbon are shown in Table 4. TABLE 4. They can also be identified by the name of the element with the mass number of the particular isotope. For example, as an alternative to 12 6 C, 13 6 C, and 14 6 C we can write carbon, carbon, and carbon About isotopes occur naturally on Earth, and another have been produced artificially. The isotopes of a given element are by no means equally abundant. For example, Some elements have only one naturally occurring isotope.
Examples: Let's determine the number of protons, neutrons, and electrons in the following isotopes. The different isotopes of an element are identified by writing the mass number of the atom in the upper left corner of the symbol for the element. If the atoms are neutral, they also must contain six electrons.
The only difference between these isotopes is the number of neutrons in the nucleus. Click here to check your answer to Practice Problem 1. Much of what is known about the structure of the electrons in an atom has been obtained by studying the interaction between matter and different forms of electromagnetic radiation. Electromagnetic radiation has some of the properties of both a particle and a wave.
Particles have a definite mass and they occupy space. Waves have no mass and yet they carry energy as they travel through space. In addition to their ability to carry energy, waves have four other characteristic properties: speed, 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 units of cycles per second s -1 or hertz Hz. The idealized drawing of a wave in the figure below illustrates the definitions of amplitude and wavelength.
The wavelength l is the smallest distance between repeating points on the wave. The amplitude of the wave is the distance between the highest or lowest point on the wave and the center of gravity of the wave. If we measure the frequency v of a wave in cycles per second and the wavelength l in meters, the product of these two numbers has the units of meters per second.
0コメント