It's an average number allowing for the relative abundances of different isotopes.
The mass of boron-11 is approximately 11 atomic mass units (amu).
The atomic mass of an atom with 11 protons and 12 neutrons is calculated by adding the number of protons and neutrons together. In this case, the atomic mass would be 11 (protons) + 12 (neutrons) = 23 atomic mass units.
Subtract the atomic # from the atomic mass. Atomic number = number of Protons. Atomic mass = total nucleons (Protons + Neutrons).Atomic # = 11 and Atomic Mass = 23. So 23-11 = 12 Neutrons.
The atomic mass of boron is approximately 10.81 atomic mass units.
The approximate mass is 11. Technically you could express this in units of daltons as 11 Da (Daltons previously called amu, Atomic Mass unit, or as 11 (the dimensionless, relative atomic mass which chemists simply call atomic weight) .
The mass of boron-11 is approximately 11 atomic mass units (amu).
The atomic mass of an atom with 11 protons and 12 neutrons is calculated by adding the number of protons and neutrons together. In this case, the atomic mass would be 11 (protons) + 12 (neutrons) = 23 atomic mass units.
Subtract the atomic # from the atomic mass. Atomic number = number of Protons. Atomic mass = total nucleons (Protons + Neutrons).Atomic # = 11 and Atomic Mass = 23. So 23-11 = 12 Neutrons.
The atomic mass of boron is approximately 10.81 atomic mass units.
The atomic mass of boron-11 (B-11) can be calculated by setting up an equation based on the given average atomic mass of boron and the known atomic mass and abundance of boron-10 (B-10). Since the average atomic mass is a weighted average of the isotopes, the equation would be: (mass of B-10 * % abundance of B-10) + (mass of B-11 * % abundance of B-11) = average atomic mass of boron. Solving this equation will give you the atomic mass of B-11.
The approximate mass is 11. Technically you could express this in units of daltons as 11 Da (Daltons previously called amu, Atomic Mass unit, or as 11 (the dimensionless, relative atomic mass which chemists simply call atomic weight) .
The atomic number of Sodium is 11, which means it has 11 protons in its nucleus. The atomic mass of Sodium is approximately 23 amu (atomic mass units), which is the weighted average of all the isotopes of Sodium found in nature.
Atomic Mass = 11 amu
Sodium is a meta element. Atomic mass of it is 23. Atomic number of it is 11.
11
The approximate mass is 11. Technically you could express this in units of daltons as 11 Da (Daltons previously called amu, atomic mass unit, or as 11 (the dimensionless, relative atomic mass which chemists simply call atomic weight) .
The atomic mass number is calculated by adding the number of protons and neutrons in the nucleus. In this case, the isotope with atomic number 5 and 6 neutrons would have an atomic mass number of 11 (5 protons + 6 neutrons = 11 atomic mass number).