Answer:
18F- contain 9 protons,10 electrons and 9 neutons.
Explanation:
18F- is the anionic form of fluorine atom in which fluorine atom gains an electron to become one unit negative charged.
In a normal fluorine atom there are 9 electrons,9 protons and 9 neutrons.As the fluorine atom gains an electron to become 18F- that contain 9+1=10 electrons.
on the other hand there is no change in the number of proton and neutron in 18F-.From that point of view it can be said that the proton and neutron number of 18F-is same as that of 18F which means the 18F- will contain 9 protons and 9 neutrons.
