This atom has three neutrons. The atomic mass number is the sum of the protons and neutrons. All atoms of the same element have the same number of protons (lithium has three), so the neutrons have to account for the rest of the mass. 6 (the mass number)-3 (the number of protons in a lithium atom)=3. So this atom must have three neutrons.
By consulting a periodic table, you can find the atomic number of lithium (which equals its proton number), as well as its average number of neutrons (represented by the mass number - simply take the proton number away from the mass number).
Atomic number is the number of protons in a nuclide. This identifies the element. Mass number is the number of nucleons in a nuclide, a nucleon being a proton or a neutron. This, together with the atomic number, identifies which isotope of the element it is.
The number of protons will always be 3 in each Li atom, and either 3 or 4 neutrons, depending on the Li atom's isotope. 6Li has 3 protons, while 7Li has 4. All other isotopes of Lithium are unstable.
an atom of carbon-12 is about twice as heavy as an atom of oxygen-16.
This atom has three neutrons. The atomic mass number is the sum of the protons and neutrons. All atoms of the same element have the same number of protons (lithium has three), so the neutrons have to account for the rest of the mass. 6 (the mass number)-3 (the number of protons in a lithium atom)=3. So this atom must have three neutrons.
Lithium with a mass number of 8 will have 3 protons. The mass number represents the total number of protons and neutrons in an atom's nucleus, and since lithium has an atomic number of 3, it means it has 3 protons.
The mass number of lithium is 7. This number represents the total number of protons and neutrons in the nucleus of a lithium atom.
Lithium's mass number is 6.941.
Lithium has 3 protons. The atomic number and the number of protons will be the same.
Atomic number is the number of protons in the nucleus of an atom while the mass number is the sum of the protons and neutrons in the nucleus of an atom. for example lithium has an atomic number of 3 and a mass number of 7. Therefore lithium has 3 protons and 4 neutrons.
Lithium is element #3. That, of course, is the atomic number - the number of protons. The atomic mass will of course depend on the specific isotope. The most common isotope is Lithium-7, that is, atomic mass = 7. Lithium-6 also occurs in nature as a stable isotope.
It tells us the total mass of Protons and Neutrons, in AMU, Atomic Mass Units.
The rest mass of a lithium atom can be calculated by adding up the masses of its protons and neutrons. Lithium has 3 protons and 4 neutrons, so the calculated mass would be (31.00727252 + 41.008665 = 7.01600472 u). The rest mass of a lithium atom is approximately 7.016 u, so the difference between the calculated and rest mass is essentially zero.
The number of protons in the nucleus is given by the atomic number. So in your example, this would be atomic number 3 (lithium). It will have atomic mass of 7 (3 protons + 4 neutrons), and a charge of 0 since there are also 3 electrons to balance the 3 protons.
lithium
6.941 is the average mass of lithium's isotopes. The majority of lithium (on average about 92.5%) is lithium-7 with 3 protons and 4 neutrons while about 7.5% is lithium-6 with 3 protons and 3 neutrons. A number of other isotopes exist but only in trace amounts.