if you are referring to the isotope number and the hyphen isn't making the six negative rather than just connecting it to the word lithium, then the Atomic Mass would be 6, if you are meaning to show the negative 6 as the ion, let me first start off by saying that a negative 6 ion would not affect the atomic mass on an atom because the atomic mass is not influenced by electrons, which is what forms ions, this is because an electron is very small, and about 1/1,800 the weight of an atom, it is approximate, but that is the general area
4 electrons, 2 valence electrons
Germanium has 32 electrons.
Xenon has 54 electrons.
Argon has 18 electrons.
Roentgenium has 111 electrons.
8 electrons
16 electrons
20 electrons
97 electrons
4 electrons.
6 electrons
4 electrons, 2 valence electrons
Germanium has 32 electrons.
Xenon has 54 electrons.
Argon has 18 electrons.
15 total electrons, 3 valence electrons
Roentgenium has 111 electrons.