- Isotope, one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties. Every chemical element has one or more isotopes.
- Isotopes are: atoms of the same element that have the same number of neutrons. Atoms of the same element that have different number of protons. Atoms of the same element that have different number of electrons. Atoms of the same element that have different number of neutrons. None of the above.
The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses. Mass is the word for how much substance (or matter) something has. Things with different masses have different weights. Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass.
Isotopes Are Atoms Of The Same Element That Have Different Group Of Answer Choices
Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons. Isotopes have different mass numbers, though, because they have different numbers of neutrons.
The word isotope, meaning at the same place, comes from the fact that isotopes are at the same place on the periodic table.
Isotopes are atoms of the same element (same atomic number, same number of protons per atom) but have different Atomic Mass, caused by a differing number of neutrons. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. 1 The term isotope is formed from the Greek roots isos ( ἴσος 'equal') and topos ( τόπος 'place'), meaning 'the same place'; thus, the meaning behind the name is that different isotopes of a single element occupy the same. Isotopes of the same element must have the. Atoms of 160, 170, and 180 have the same number of protons, but a different number of neutrons. Which symbol represents atoms that are isotopes of each other? All the isotopes of a given atom have.
In a neutralatom, the number of electrons equals the number of protons. Isotopes of the same element also have the same number of electrons and the electronic structure. Because how an atom acts is decided by its electronic structure, isotopes are almost the same chemically, but different physically to their original atoms.
Heavier isotopes react chemically slower than lighter isotopes of the same element. This 'mass effect' is larger for protium (1H) and deuterium (2H), because deuterium has twice the mass of protium. For heavier elements, the relative atomic weight ratio between isotopes is much less, and the mass effect is usually small.
Stability[change | change source]
Atomic nuclei are protons and neutrons held together by the nuclear force.
Because protons are positively charged, they repel each other. Neutrons, which are neutral, stabilize the nucleus. Because they are in the nucleus, the protons are pushed slightly apart. This reduces the electrostatic repulsion between the protons. They still exert the attractive nuclear force on each other and on protons. One or more neutrons are necessary for two or more protons to bind into a nucleus. As the number of protons increases, so does the number of neutrons needed to have a stable nucleus.
In nature some elements only have a single isotope. For example, fluorine-19 (19F) is the only stable isotope, of several, of fluorine. Other elements have many isotopes. For example, xenon has 9 isotopes. Of the 81 elements with a stable isotope, the largest number of stable isotopes for any element is ten (for the element tin).
Some isotopes are radioactive. These are called radioactive isotopes. Others are not radioactive. These are called stable isotopes.
Hydrogen has three common isotopes. The most common isotope of hydrogen is called protium (1H). A hydrogen atom with an extra neutron (atomic mass of 2) is called deuterium (2H). Hydrogen with one proton and two neutrons (atomic mass of 3) is called tritium (3H). Protium and deuterium are stable isotopes, while tritium is a radioactive isotope.
The heaviest elements in the periodic table are all radioactive. All of the isotopes of radon, thorium, and uranium are radioactive, since they are very heavy. This is because the nuclear forces inside the nucleus of the atom have a tough time holding together all the particles with so many protons and neutrons inside.
Related pages[change | change source]
Isotopes
Isotopes are atoms of the same element that contain different numbers of neutrons. For these species, the number of electrons and protons remain constant. This difference in neutron amount affects the atomic mass (A) but not the atomic number (Z). In a chemical laboratory, isotopes of an element appear and react the same. For this reason, it is difficult to distinguish between an atom's isotopes. In contrast, nuclear scientists can identify and separate different types of atomic nuclei. The technology required for this process is more sophisticated that what could be found in a typical chemical laboratory.
The element carbon ((ce{C})) has an atomic number of 6, which means that all neutral carbon atoms contain 6 protons and 6 electrons. In a typical sample of carbon-containing material, 98.89% of the carbon atoms also contain 6 neutrons, so each has a mass number of 12. An isotope of any element can be uniquely represented as ({}_Z^{A}X) where X is the atomic symbol of the element. The isotope of carbon that has 6 neutrons is therefore (ce{_6^{12}C}) The subscript indicating the atomic number is actually redundant because the atomic symbol already uniquely specifies Z. Consequently, it is more often written as (ce{^{12}C}), which is read as “carbon-12.” Nevertheless, the value of (Z) is commonly included in the notation for nuclear reactions because these reactions involve changes in (Z).
Most elements on the periodic table have at least two stable isotopes. For example, in addition to (ce{^{12}C}), a typical sample of carbon contains 1.11% (ce{_6^{13}C}), with 7 neutrons and 6 protons, and a trace of (ce{_6^{14}C}), with 8 neutrons and 6 protons. The nucleus of (ce{_6^{14}C}) is not stable, however, but undergoes a slow radioactive decay that is the basis of the carbon-14 dating technique used in archeology. Many elements other than carbon have more than one stable isotope; tin, for example, has 10 isotopes. There are about twenty elements that exist in only one isotopic form (sodium and fluorine are examples of these).
An important series of isotopes is found with hydrogen atoms. Most hydrogen atoms have a nucleus with only a single proton. About 1 in 10,000 hydrogen nuclei, however, also has a neutron; this particular isotope is called deuterium. An extremely rare hydrogen isotope, tritium, has 1 proton and 2 neutrons in its nucleus. Figure (PageIndex{1}) compares the three isotopes of hydrogen.
Isotopes Are Atoms Of The Same Element That Have Different *
There are currently over 3,500 isotopes known for all the elements. When scientists discuss individual isotopes, they need an efficient way to specify the number of neutrons in any particular nucleus. A/Z and symbol-mass formats can be used to display periodic table information. When viewing either of these two notations, isotopic differences can be obtained.
The discovery of isotopes required a minor change in Dalton’s atomic theory. Dalton thought that all atoms of the same element were exactly the same.
Look at the A/Z formats for the three isotopes of hydrogen in Table (PageIndex{1}). Note how the atomic number (bottom value) remains the same while the atomic masses (top number) are varied. All isotopes of a particular element will vary in neutrons and mass. This variance in mass will be visible in the symbol-mass format of same isotopes as well.
| Common Name | A/Z formats | symbol-mass format | Expanded Name |
|---|---|---|---|
| Hydrogen | (mathrm{^{1}_{1}H}) | (text{H-1}) | hydrogen-1 |
| Deuterium | (mathrm{^{2}_{1}H}) | (text{H-2}) | hydrogen-2 |
| Tritium | (mathrm{^{3}_{1}H}) | (text{H-3}) | hydrogen 3 |
Isotopes Are Atoms Of The Same Element That Have Different *
Both A/Z or symbol-mass formats can be utilized to determine the amount of subatomic particles (protons, neutrons, and electrons) contained inside an isotope. When given either format, these mass values should be used to calculate the number of neutrons in the nucleus.