But the molecular formulas of allotropes can be either equal or different from each other. Therefore, the chemical and physical properties of allotropes can be different from each other. Allotropy is the term used to describe the presence or absence of allotropes for a particular chemical element. All chemical elements do not have allotropes. Only some elements show allotropy.
Some common examples are discussed below. Carbon is a major chemical element that shows allotropy. The most common allotropes of carbon are graphite and diamond. Both Graphite and diamond are composed of only carbon atoms. But the molecular structure, hybridization of carbon atoms and other physical properties of them are different from each other.
Figure Chemical structures and the appearances of Diamond and Graphite. The allotropes of oxygen are Dioxygen O 2 and Ozone O 3. Both of them are in the gaseous phase in nature and are different from each other through the molecular structure, chemical and physical properties. Sulfur in nature is found as S 8 units. These units are composed of eight sulfur atoms. Here, one sulfur atom is bonded to two other sulfur atoms forming a cyclic structure.
These cyclic structures can be either in rhombic structure, needle form Monoclinic or orthorhombic form. The general structure of S 8 is the crown structure. Figure Crown structure of S8. Allotropy is defined for molecules in the physical state. Therefore, liquid water and ice are not allotropes even though both are composed of only water molecules H 2 O. Isotopes are different forms of atomic structures of the same chemical element.
Generally, an atom is made out of a nucleus and an electron cloud surrounding this nucleus. The nucleus is composed of protons and neutrons whereas the electron cloud is composed only of electrons. An element is composed of a unique number protons. The atomic number of an element is the number of protons. Therefore, each chemical element has a unique atomic number. The periodic table of elements is built based on the atomic numbers of elements.
Here, the chemical elements are arranged in the ascending order of the atomic number. The atomic weight is just the number of protons plus the number of neutrons. Carbon always has 6 protons, so 6 more neutrons and it will be Carbon Carbon has 7 neutrons, and Carbon has 8 neutrons. There is also Carbon-8 to Carbon, but these can only be made in a laboratory and they are very unstable.
Some isotopes will be more stable than others. In carbon, carbon is much more stable and abundant than carbon or carbon Carbon is unstable but has a very long half-life more on this in the next section.
Isotopes are the reason that the atomic weights on the periodic table are not nice whole numbers. Carbon weighs exactly 12 amu, carbon weighs 13 amu, etc. In other words, almost all carbon is carbon, but there is enough carbon and carbon to increase the average weight of carbon to Similarly, hydrogen has an atomic weight of 1. Most hydrogen is hydrogen-1 protium , but there are small amounts of hydrogen-2 deuterium and hydrogen-3 tritium.
These isotopes of hydrogen get fancy names because they each have unique applications. In general, stable isotopes behave pretty much the same. One use for similar-behaving isotopes is as a tracer. Around the globe, different elemental isotopes occur in slightly different ratios.
This information is a great tool for assessing environmental impact like water flow, or solving geological puzzles about the planet before human record. Different isotopes can be placed in the body along with pharmaceuticals to track the drug movement. Some isotopes are radioactive , which means that the isotope is not stable.
To achieve a more stable configuration, these atoms may shed some number of protons and neutrons. This can let us change lead into gold! Yes, changing lead into gold has actually been accomplished by scientists. Unfortunately, making this lead isotope and then converting it into a gold isotope is extremely expensive.
Half-life is the amount of time it takes a radioactive isotope to decay into a different isotope or element. If you started with grams of something that had a half life of 10 minutes, then every 10 minutes you would have half of what you started with.
After 10 minutes you would have 50 grams, after 10 more minutes you would have 25 grams, ater 10 more minutes you would have Have you heard of carbon dating? It is a technique used to evaluate how old something is. Carbon dating works by measuring the ratio of carbon to carbon They show different physical properties. Among all the chemical elements, carbon, oxygen, sulfur and phosphorous are the major elements that have allotropes.
Carbon has a large number of allotropes. The eight allotropes of carbon differ largely from each other. For example, diamond is the strongest allotrope of carbon whereas graphite is less strong. Carbon nanotubes, fullerene, and amorphous carbon are some other allotropes of carbon.
For the element oxygen, there are two common allotropes as O2 and O3. O2 is abundant than O3. Normally, in nature, some allotropes are more abundant than others because of their stability.
Phosphorus has three allotropes as red, white and black phosphorus. From these, red and white phosphorus are the most common. Allotropes differ from each other due to the atomic arrangement, the number of atoms, etc.
Isotopes are different forms of atoms of the same chemical element. They are different from each other as they have a different number of neutrons. Since the neutron number is different, their mass number also differs.
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