How are the atomic mass unit and the atomic weight related?

Answer 1

The mass number is the total amount of protons and neutrons in an atom (the number of protons is the same as the number of electrons) The atomic number is the number of protons (or electrons) in an atom. To find out the number of neutrons in an atom, you need to take the atomic number from the mass number An atom is normally written like this: Mass number Ca Atomic number The Mass number can be written as (A) and the atomic number can be writtens as (Z)

Answer 2

Isotopes of the elements are quoted with two numbers. The one which determines the name of the element is the atomic number which is the number of protons in the nucleus. The total of protons plus neutrons is the other number, which can vary for any one element's isotopes, this used to be called the atomic weight but now it seems to be Atomic Mass number.

Thus uranium has 92 protons, but the two main isotopes are 235 and 238, so they have 143 and 146 neutrons respectively

Answer 3

The atomic weight (IUPAC recommend the use of the word weight in the case of elements) of an element is a multiple of the atomic mass unit.

The atomic mass unit is 1/12 from the atomic mass of the isotope carbon 12 in ground state.

Example: atomic weight of hydrogen is 1,00794 u.

Answer 4

The atomic mass unit (amu) is a unit of mass used to express atomic and molecular weights. Atomic weight, on the other hand, is the average mass of an element's isotopes weighted by their natural abundance. In essence, atomic weight is essentially the same as atomic mass unit but is more commonly used in chemistry to refer to the weighted average of isotopes.

Answer 5

The mass of an electron is counted when the atomic mass is added up, but the mass of an electron is so insignificant it is taken into account like a zero.