It's an average number allowing for the relative abundances of different isotopes.
fluorine
The atomic mass number for fluorine is 18.9998, rounded to 19. Most fluorine is 19F but some is 18F with a half-life of 109.77 minutes.
Fluorine is a non metal element. Atomic mass of it is 19.
Fluorine is a non meta element. Atomic mass of it is 19.
Fluorine is a meta element. Atomic mass of it is 19.
Fluorine is a metal element. Atomic Mass of it is 19.
fluorine
Fluorine is a non metal element. Atomic mass of it is19.
Atomic weight of fluorine = 6,022 141 78.1023 (Avogadro number) . 266,889 (the mass of atoms)/8,46.1024 (the number of atoms). The IUPAC 2005 atomic weight of fluorine is 18,998 403 2(5).
The atomic mass number for fluorine is 18.9998, rounded to 19. Most fluorine is 19F but some is 18F with a half-life of 109.77 minutes.
Fluorine is a non metal element. Atomic mass of it is 19.
Atomic number of Fluorine is 9.Mass number of Fluorine is 19.
Fluorine is a non metal element. Atomic mass of it is 19.
Fluorine is a non metal element. Atomic mass of it is 19.
Fluorine is a non meta element. Atomic mass of it is 19.
Fluorine is a meta element. Atomic mass of it is 19.
According to the periodic table: F atomic number 9, atomic mass of 18.998403