One atom of helium has two protons in its nucleus. A neutral atom of helium also has two electrons.Know More
The number of protons in an element is equal to the element's atomic number. Helium has the atomic number 2, which means it has two protons. An element's atomic number appears directly above its symbol in some versions of the periodic table. In other versions, it appears in the top left corner of the element's square.
Helium was discovered by Sir William Ramsay in 1895. Its name is derived from the Greek word for "sun." This gas is found in the air, as well as in natural gas deposits.Learn more about Atoms & Molecules
Mercury has 80 protons, which is also the element's atomic number. Mercury has an atomic weight of 200.59 amu, and its chemical symbol is Hg.Full Answer >
The chemical element iodine has exactly 53 protons. The element also has 53 electrons, since all atoms have the same number of protons as they do electrons in order to make the atom neutral.Full Answer >
The nucleus of helium contains two neutrons and two protons. Around the nucleus of helium there are two electrons in the 1s orbital. These have opposite spins.Full Answer >
Helium has two valence electrons. As an element, helium is very stable and contains a single s-orbital on its outer shell.Full Answer >