The mass number in Helium represents how much space a single helium atom takes up (not including electrons, because electrons can be bonded, and my come and go)
4 is the mass number of helium (mass number = number of protons + number of neutrons)
The isotopic notation for helium-4 is ^4He. This notation denotes the element's atomic number and mass number, which for helium-4 are 2 (atomic number) and 4 (mass number) respectively.
4He or He4. 4 stands for the mass number of Helium Mass number = number of protons + number of neutrons Since the atomic number or number of protons in helium is 2, the number of neutrons in He-4 is also 2.
Helium is lighter than air because of atomic mass. Helium is element number two, whereas oxygen is element number 8. Oxygen has an atomic mass of 16, and helium has a mass of 4, so helium is 4 times lighter than air. (Atomic mass is the total mass of protons, neutrons, and electrons in a single atom.)
atomic mass is the number of protons in that element molecule.
The atomic number of helium is 2. Its mass is 4.002602 u ± 0.000002 u
Most helium has a mass number of 4. The rare 3He isotope has a mass number of 3. The mass number is the integer total of protons and neutrons for a given isotope. For example radioactive carbon-14 has a mass number of 14, while carbon-12 (the most common stable form) has a mass number of 12.
Helium is a metal element. Atomic number of it is 2.
4 is the mass number of helium (mass number = number of protons + number of neutrons)
Helium's atomic number is 2 and its atomic mass is 4
The isotopic notation for helium-4 is ^4He. This notation denotes the element's atomic number and mass number, which for helium-4 are 2 (atomic number) and 4 (mass number) respectively.
4He or He4. 4 stands for the mass number of Helium Mass number = number of protons + number of neutrons Since the atomic number or number of protons in helium is 2, the number of neutrons in He-4 is also 2.
Helium is lighter than air because of atomic mass. Helium is element number two, whereas oxygen is element number 8. Oxygen has an atomic mass of 16, and helium has a mass of 4, so helium is 4 times lighter than air. (Atomic mass is the total mass of protons, neutrons, and electrons in a single atom.)
Helium-4.
Helium
atomic mass is the number of protons in that element molecule.
Helium is number 2 on the Periodic Table, and the number of its mass is 4. So, therefore it has 2 protons, 2 neutrons, and 2 electrons !