Element Defenition
There are 115 known elements, although the periodic table has space for 118 of them. Elements 113, 115, and 118 have been claimed, but require verification to earn a place on the periodic table. Research is also underway to make element 120. When element 120 is made and verified, the periodic table will need to be changed to accommodate it!
The element is a single chemical substance can not be decomposed into other substances. Some examples are the elements oxygen, nitrogen, hydrogen, iron, aluminum, gold, silver, mercury and platinum. The natural elements are generally present in the form of compounds, such as hydrogen, for example contained in the water and carbohydrates. Some elements such as oxygen, nitrogen, sulfur, gold, and platinum in addition to compounds also exist in the free state. As we know, oxygen and nitrogen contained in the air.
The element itself is divided over the metals and non-metals, some examples of the metal element is aluminum, iron (ferum), gold (aurum), silver (arguntum), and mercury (hidrargirum).
Metallic element has properties such as:
· Except mercury, everything is a solid at room temperature (25 degrees Celsius)
· A good conductor of electricity and heat
· Shiny if rubbed
Some examples of non-metallic element is nitrogen, Oxygen, Carbon, Sulfur (sulfur) and chlorine. The non-metallic element has properties such as:
· Which is a solid generally brittle, such as charcoal (carbon)
· Nothing is a solid, liquid, or gaseous substance at room temperature (25 degrees Celsius)
· Not shiny when rubbed, except diamonds (another form of carbon)
ALKALI METALS
Thare lithium, sodium, potassium, rubidium, cesium, and francium.These elements are best marked by their reactivity. Physically they are soft, shiny (when freshly prepared) solids with low melting points; they conduct electricity well. They all have one valence electron that they lose easily to almost any electronegative substance. Alkali metals are never found in their elemental form outside the lab because they are too reactive. Even the smallest amount of oxygen or water would react with the metal. For this reason, alkali metals have no structural use. They must be kept under inert liquids such as kerosene or in inert gases (nitrogen suffices for any of these elements other than lithium). Alkali metals have many uses in both biological life and industry. Francium, however, is radioactive and decays rapidly to other elements, so it has no commercial use and its chemical properties are vaguely understood. All oxidize easily to the +1 oxidation state.
HALOGEN
The halogens are five non-metallic elements found in group 17 of the periodic table. The term "halogen" means "salt-former" and compounds containing halogens are called "salts". All halogens have 7 electrons in their outer shells, giving them an oxidation number of -1. The halogens exist, at room temperature, in all three states of matter:
-Solid : Iodine, Astatine
-Liquid : Bromine
-Gas : Fluorine, Chlorine.
NOBLE GAS
Noble gas is the designation for a group VIIIA elements. The elements are the noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). The noble gases derived from the air, but radon is obtained from uranium rock cavity. Helium apart from information obtained from outdoor air can also be obtained from natural gas separation. The noble gases are persistently the most stable element. This is evidenced by the presence in the universe is in the form of an element. Stability caused by the very high ionization energy and the valence electrons duplet for helium and octets for other noble gas elements.
BalasHapusThe number of protons, electrons, and neutrons found in Ca 2+ cations, if known atomic number and mass number is 20 and 40.?
Proton = 20, electrons = 20 - 2 = 18, neutron = 40 - 20 = 20
HapusWhere we can to find the alkali metal??
BalasHapusAlkali metals are not free in nature. This is because the reactivity of large alkaline metals is so easy to bind to other elements.
HapusWould you please explain about nuclear reactions?
BalasHapusIn nuclear physics, a nuclear reaction is a process in which two nuclei or nuclear particles collide, to produce different results from the original product. In principle a reaction can involve more than two collided particles, but the event is very rare. When the particles collide and separate without changing (except perhaps in the energy level), this process is called a collision and not a reaction.
HapusKnown two nuclear reactions, namely nuclear fusion reactions and nuclear fission reactions. The nuclear fusion reaction is the melting of two or more nuclei into new atoms and generates energy, also known as a clean reaction. The nuclear fission reaction is the reaction of atomic division due to the collision of other nuclei, and produces new mass and smaller atoms, and electromagnetic radiation. Fusion reactions also produce intense alpha, beta and gamma-ray radiation for humans.
An example of a nuclear fusion reaction is a reaction that occurs in almost all the star cores in the universe. The hydrogen bomb weapon also utilizes the principle of an uncontrollable fusion reaction.
Examples of fission reactions are the explosion of nuclear weapons and nuclear power plants.
Common elements used in nuclear fission reactions are Plutonium and Uranium (especially Plutonium-239, Uranium-235), whereas in nuclear fusion reactions are Lithium and Hydrogen (especially Lithium-6, Deuterium, Tritium).
What is the difference between elements and compounds?
BalasHapusElements and compounds are pure chemical substances found in nature. The difference between an element and a compound is that an element is a substance made of same type of atoms, whereas a compound is made of different elements in definite proportions. Examples of elements include iron, copper, hydrogen and oxygen. Examples of compounds include water (H2O) and salt (Sodium Chloride - NaCl)
Hapus