The brackets are used for isotopic elements--those with variable numbers of neutrons. The atomic weight of the most stable isotope is the one in brackets.
You know, this is a terrible way to be getting your chemistry coursework done.
Here you go:
www.lenntech.com/periodic-chart-elements/tc-en.htm
There you go.
Because its a synthetic element.
The number that appears in brackets is the most stable isotope of technetium.
Probably because technetium does not occur naturally; all its isotopes are radioactive with short half-lives compared with naturally occurring radioactive elements such as uranium.
The standardized atomic weight of technetium is [98] amu.
Because its a Synthetic Element!!!!!!!!
because you touch yourself at night
I assume you mean the atomic mass. Its atomic mass is 98.91g/mol
why is the atomic mass of technitium usually in brackets?
Any time you see the atomic mass of an element in brackets on the periodic chart, that number represents the mass number of the longest-lived or best-known isotope of that element. In other words there is no stable isotope, i.e. all forms of it are radioactive.
Titanium(Ti)
because it is an isotope???
I assume you mean the atomic mass. Its atomic mass is 98.91g/mol
why is the atomic mass of technitium usually in brackets?
Any time you see the atomic mass of an element in brackets on the periodic chart, that number represents the mass number of the longest-lived or best-known isotope of that element. In other words there is no stable isotope, i.e. all forms of it are radioactive.
Titanium(Ti)
because it is an isotope???
Technetium which has an atomic mass of 98.
The atomic mass (not molecular weight) of technetium-99 is 98,906 254 7(21).
The atomic number of technetium (Tc) is 43.The atomic weight of Tc is 98 grams per mole.See the Web Links to the left of this answer for a periodic table with more information about this element!
The atomic nucleus of technetium contain 43 protons and electrons.For each isotope the number of neutrons is different. Number of neutrons = Mass number of an Tc isotope - 43
Atomic mass
Bromine, because Bromine has an atomic mass of only 5.
Technetium has 34 isotopes, with no stable isotopes