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25 Οκτ 2024 · Helium, chemical element, inert gas of Group 18 (noble gases) of the periodic table. The second lightest element, helium is a colorless, odorless, and tasteless gas that becomes liquid at -268.9 degrees Celsius. The boiling and freezing points of helium are lower than those of any other known substance.
Helium (from Greek: ἥλιος, romanized: helios, lit. 'sun') is a chemical element; it has symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table.
After hydrogen, helium is the second most abundant element in the universe. It is present in all stars. It was, and is still being, formed from alpha-particle decay of radioactive elements in the Earth. Some of the helium formed escapes into the atmosphere, which contains about 5 parts per million by volume.
- Helium is the second lightest and second most abundant element in the observable universe. - It plays a vital role in various industries including healthcare, aerospace, and technology. - Helium is a colorless, odorless, and tasteless gas that belongs to the noble gases group in the periodic table. Historical Background
13 Ιουν 2023 · Helium is a noble gas meaning that it exists only as atoms of the elements that are never bonded to other atoms. Figure 3.3 is a representation of the helium atom showing its 2 electrons. The Lewis symbol of helium is simply He with 2 dots. This shows a very important characteristic of atoms.
15 Δεκ 2022 · Helium is the second most abundant element in the universe. Helium is a noble gas and its symbol is He. The elements in Group 18 (VIIIA) of the periodic table are noble gases. It is colorless, odorless, and tasteless. It is monatomic and has an extremely low boiling point.
Helium is a chemical element. Its official symbol is He, and its atomic number is 2, which means it has two protons in its nucleus. Helium was named after Helios – the Greek Titan of the Sun – because it was first observed when analysing sunlight during a solar eclipse in 1868.
