The element fluorine forms a(n) with the charge . The symbol for this ion is , and the name is . The number of electrons in this ion is

A chemical element exhibiting the symbol F and atomic number 9 is fluorine. It prevails as an extremely toxic pale yellow diatomic gas at normal circumstances and is the lightest halogen. It is exceptionally reactive as it reacts with all the other elements except for helium, argon, and neon, and is the most electronegative element.

Fluorine like halogens produces an anion with a charge of -1 to acquire stability. The symbol for this ion is F-, and the name given to the ion is fluoride ion. The atomic number of fluorine is 9, therefore, the number of electrons in this anion is 9+1 = 10.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.