Helium is an element of the periodic table that is composed of subatomic particles including protons, neutrons and electrons. The atomic number of helium is 2, which means it contains two protons and two electrons. The most common isotope of helium contains two neutrons.Know More
Helium is designated by the chemical symbol He and is the lightest of the noble gases. Like the other noble gases, helium is nonreactive. It has the lowest boiling and melting points of all the elements.
Helium is the second most abundant element in the universe after hydrogen, but it is rare on Earth. Most of the helium used in industry comes from natural gas, and the majority of the Earth's helium supply is extracted from wells in Texas, Oklahoma and Kansas.Learn more in Chemistry
Oxygen is an element, not a compound, and can be found on the periodic table with the atomic number eight. Oxygen is primarily found in two common forms, oxygen gas and in air. Oxygen gas molecules are made of two oxygen atoms covalently bonded together, but it is still considered an element; air is a mixture of mainly oxygen and nitrogen, which makes it a compound.Full Answer >
Silicon is the 14th element on the periodic table. It has an atomic weight of 28.0855 and has the symbol Si. Silicon appears as a brown powder in its amorphous state and in a gray metallic crystalline form.Full Answer >
According to the Periodic Table, iron is the element that has 26 protons. Its atomic number, correspondingly, is 26. This makes iron an element of middling weight, which may be surprising considering its reputation as a metal of great strength.Full Answer >
The lightest element on the periodic table is hydrogen. The atomic weight of hydrogen is 1.00794 and the atomic number is 1. Hydrogen is the most abundant element on the periodic table with 75 percent of the mass of the universe consisting of hydrogen.Full Answer >