What is the atom make up for helium?

Answer 1

Helium From Wikipedia, the free encyclopedia

This article is about the chemical element. For other uses, see Helium (disambiguation).

hydrogen ← helium → lithium -
↑
He
↓
Ne

2He

Periodic table

Appearance Colorless gas, exhibiting an red-orange glow when placed in a high voltage electric field


Spectral lines of helium General properties Name, symbol,numberhelium, He, 2 Pronunciation /ˈhiːliəm/hee-lee-əm Element category noble gases Group, period,block18, 1, Standard atomic weight 4.002602(2) Electron configuration 1s2 Electrons pershell2 (Image) Physical properties Phase gas Density (0 °C, 101.325 kPa)
0.1786 g/L Liquid density atm.p.0.145 g·cm−3 Melting point (at 2.5 MPa) 0.95 K, −272.20 °C, −457.96 °F Boiling point 4.22 K, −268.93 °C, −452.07 °F Critical point 5.19 K, 0.227 MPa Heat of fusion 0.0138 kJ·mol−1 Heat of vaporization 0.0829 kJ·mol−1 Molar heat capacity 5R/2 = 20.786 J·mol−1·K−1 Vapor pressure (defined by ITS-90) P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1.23 1.67 2.48 4.21 Atomic properties Electronegativity no data (Pauling scale) Ionization energies 1st: 2372.3 kJ·mol−1 2nd: 5250.5 kJ·mol−1 Covalent radius 28 pm Van der Waals radius 140 pm Miscellanea Crystal structure hexagonal close-packed Magnetic ordering diamagnetic[1]Thermal conductivity 0.1513 W·m−1·K−1 Speed of sound 972 m·s−1 CAS registry number 7440-59-7 Most stable isotopes Main article: Isotopes of helium iso NA half-life DM DE (MeV) DP 3He 0.000137%* 3He is stable with 1 neutron 4He 99.999863%* 4He is stable with 2 neutrons *Atmospheric value, abundance may differ elsewhere. v · d · e · r

Helium ( /ˈhiːliəm/hee-lee-əm) is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Next to hydrogen, it is the second most abundant element in the universe and accounts for 24% of the elemental mass of our galaxy.

An unknown yellow spectral line signature in sunlight was first observed during a solar eclipse in 1868 by French astronomer Jules Janssen. Janssen is jointly credited with the discovery of the element with Norman Lockyer, who observed the same eclipse and was the first to propose that the line was due to a new element, which he named helium after the Greek God Helios. In 1903, large reserves of helium were found in natural gas fields in parts of the United States, which is by far the largest supplier of the gas.

Helium is used in cryogenics (its largest single use, absorbing about a quarter of production), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners. Helium's other industrial uses- as a pressurizing and purge gas, as a protective atmosphere for arc welding and in processes such as growing crystals to makesilicon wafers- account for half of the gas produced. A well-known but minor use is as a lifting gas in balloons and airships.[2]As with any gas with differing density from air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice. In scientific research, the behavior of the two fluid phases of helium-4 (helium I and helium II), is important to researchers studying quantum mechanics (in particular the property of superfluidity) and to those looking at the phenomena, such as superconductivity, that temperatures near absolute zero produce in matter. Helium is the second lightest element and is the second mostabundantin the observable universe, being present in the universe in masses more than 12 times those of all the heavier elements combined. Its abundance is similar to this figure in our own Sun and in Jupiter. This is due to the very high binding energy (per nucleon) of helium-4 with respect to the next three elements after helium (lithium, beryllium, and boron). This helium-4 binding energy also accounts for its commonality as a product in both nuclear fusion and radioactive decay. Most helium in the universe is helium-4, and is believed to have been formed during the Big Bang. Some new helium is being created currently as a result of thenuclear fusion of hydrogen in stars greater than 0.5 solar masses.

On Earth, the lightness of helium has caused its evaporation from the gas and dust cloud from which the planet condensed,[citation needed] and it is thus relatively rare-0.00052% by volume in the atmosphere. Most terrestrial helium present today is created by the natural radioactive decay of heavy radioactive elements (thoriumand uranium), as the alpha particles emitted by such decays consist of helium-4 nuclei. This radiogenic helium is trapped with natural gas in concentrations up to 7% by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation.

Answer 2

helium is an element

hope i helped:)

Not truly the correct answer. This is:

Actually, Helium is a non metal, and a noble gas and also an "inert gas", which means there is no space to add anything to it. You can not add other elements to it to make another type of molecule.

Not like Hydrogen and Oxygen where you can add them together and make another molecule, but with Helium you can rarely add any elements to it, you will rarely see a molecule with Helium in it.

So there are no two elements, or any elements at all on the Periodic Table that make up Helium, your question is not even that accurate. I see what you are trying to ask, but rethink your question.

I hope this helped.

From: Wasp04_Celine.

Answer 3

Helium has an atomic number of 2, which means it has 2 protons in its nucleus. It typically has 2 neutrons, making its most common isotope helium-4. This gives helium a total of 2 electrons in its electron cloud.

Answer 4

Under normal conditions, one helium atom in each molecule.

Answer 5

Helium is a gas at STP and has 2 protons, 2 electrons. He-3 isotope has 1 neutron whereas He-4 isotope has 2 neutrons.

Answer 6

Helium has 2 protons, 2 electrons and 1 or 2 neutrons.