Answer:
5 neutrons
Step-by-step explanation:
There five isotopes of lithium. The most stable and abundant is lithium-7.
Its percentage is 92.5%. It has four neutrons. All lithium isotopes have same atomic number but different atomic mass because of different number of neutrons.
Lithium-8 have five neutrons.
Lithium-9 have six neutrons.
Lithium-11 have eight neutrons.
Lithium-4 has one neutron.
Lithium is alkali metal.
It is present in 1st group.
Its atomic number is 3.
Its atomic mass is 7 amu.
Lithium salts are used in psychiatric medicine.