It isn't, as such. Isotopes of the same element have different numbers of neutrons, and neutrons have a mas of one Atomic Mass unit (amu). So isotopes have different atomic masses, but being told the number of neutrons any isotope has, will not enable you to say what element or Atomic Mass it had, unless you remembered the details for every single isotope. Even then different elements can have the same number of neutrons. Isotopes do get named after their atomic mass however - uranaium 235 has an atomic mass of 235, for instance.
The correct expression is "atomic mass of the isotope"; it is related to 1/12 of the mass of the isotope carbon-12.
average atomic massof an element=(Atomic mass of first isotope X % of that isotope) + (Atomic mass of second isotope X % of the second isotope)
It isn't, as such. Isotopes of the same element have different numbers of neutrons, and neutrons have a mas of one atomic mass unit (amu). So isotopes have different atomic masses, but being told the number of neutrons any isotope has, will not enable you to say what element or atomic mass it had, unless you remembered the details for every single isotope. Even then different elements can have the same number of neutrons. Isotopes do get named after their atomic mass however - uranaium 235 has an atomic mass of 235, for instance.
The atomic mass of the most stable isotope of Roentgenium is 281. This most stable isotope decays in around 36seconds. Oddly, it's most stable isotope has the same atomic mass as the most stable isotope of the element before: Darmstadtium.
The two main factors in determining the average atomic mass of an element are:the isotopic composition of the element (the fraction of each isotope)the atomic mass of each isotope
An isotope's mass number is the sum of the protons and neutrons in each atomic nucleus of the isotope.
Number of neutrons = Atomic mass - Atomic number Atomic number of neon: 10 Atomic mass: depending on the neon isotope, each isotope has a different mass
To calculate the atomic mass of chlorine using its naturally occurring isotopes, you can use the formula: Atomic mass = (abundance of isotope 1 × atomic mass of isotope 1) + (abundance of isotope 2 × atomic mass of isotope 2). In this case, you would multiply the atomic mass of each isotope by its respective abundance (expressed as a decimal) and sum the results to find the weighted average atomic mass of chlorine.
The most common isotope is einsteinium-253. So atomic mass is 253 for the most common isotope
195Au is an isotope of gold with a half life of about 186 days. It decays into 195Pt, an isotope of platinum. Its mass is 194.97 atomic mass units.
Atomic number is not related to isotopes.
The atomic mass of an isotope is the weighted average mass of all the isotopes of that element based on their natural abundance. It is expressed in atomic mass units (amu).