Helium
helium has 2 protons and 2 neutrons. so its atomic number is 4
The atomic number is 7. The mass number is 15. The atomic mass is 15,000 108 898 2(7).
The atomic number of deuterium (2H) is 1, as it has one proton in its nucleus. The mass number of deuterium is 2, which is the sum of the protons and neutrons in its nucleus (1 proton + 1 neutron = mass number of 2).
Symbol: He atomic #: 2 atomic mass: 4.002602
To find the number of neutrons simply subtract the atomic number from the atomic mass. In this case there are two neutrons.
Helium's atomic number is 2 and its atomic mass is 4
Hydrogen is a gas. Mass number of it is 2.
The 'standard' hydrogen atom has atomic number 1, atomic mass 1, no neutrons. Although there are 2 other isotopes of hydrogen: - (cant confirm name) which has atomic mass 2 and 1 neutron. - (cant confirm name) has atomic mass of 3 and 1 neutron. All isotopes have atomic number 1.
Helium is a metal element. Atomic number of it is 2.
The atomic number is 2, and the atomic mass is 4 (helium)
The average number of neutrons that a specific element has is equivilent to the element's atomic mass minus the that elements atomic number. For example Helium has 2 neutrons because its atomic mass (4) minus the atomic number (2) is 2.
Helium is a non metal element. Atomic mass number of it is 4.