One atom of helium has two protons in its nucleus. A neutral atom of helium also has two electrons.Continue Reading
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
The number next to isotopes signifies the sum of the number of protons plus the number of neutrons in the nucleus of an atom. For a particular element, the number of protons never changes, but the number of neutrons can vary.Full Answer >
The net electric charge of the nucleus of an atom is positive due to the presence of charge-carrying particles known as protons. The outer shell of the atom is negatively charged as a result of carrying electrons in a diffuse cloud. Atoms always have a net neutral electric charge.Full Answer >
The atomic number indicates the number of protons present in the nucleus of an atom, which is used to uniquely identify the atom, as well as its chemical properties. The atomic number is denoted by the universal symbol "Z."Full Answer >
The compact, positively-charged nucleus of an atom contains two main types of subatomic particles: protons and neutrons. Orbiting the atom's nucleus are negatively-charged subatomic particles called electrons. The mass of an atom is concentrated in the nucleus.Full Answer >