<Table> <Tr> <Th> Z </Th> <Th> Element </Th> <Th> No. of electrons / shell </Th> <Th> Group </Th> </Tr> <Tr> <Td> </Td> <Td> Hydrogen </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Helium </Td> <Td> </Td> <Td> 18 </Td> </Tr> <Tr> <Td> </Td> <Td> Lithium </Td> <Td> 2 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Beryllium </Td> <Td> 2 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Boron </Td> <Td> 2 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Carbon </Td> <Td> 2 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Nitrogen </Td> <Td> 2 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Oxygen </Td> <Td> 2 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Fluorine </Td> <Td> 2 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Neon </Td> <Td> 2 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Sodium </Td> <Td> 2 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Magnesium </Td> <Td> 2 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 13 </Td> <Td> Aluminium </Td> <Td> 2 , 8 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 14 </Td> <Td> Silicon </Td> <Td> 2 , 8 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 15 </Td> <Td> Phosphorus </Td> <Td> 2 , 8 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 16 </Td> <Td> Sulfur </Td> <Td> 2 , 8 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 17 </Td> <Td> Chlorine </Td> <Td> 2 , 8 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 18 </Td> <Td> Argon </Td> <Td> 2 , 8 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 19 </Td> <Td> Potassium </Td> <Td> 2 , 8 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 20 </Td> <Td> Calcium </Td> <Td> 2 , 8 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 21 </Td> <Td> Scandium </Td> <Td> 2 , 8 , 9 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 22 </Td> <Td> Titanium </Td> <Td> 2 , 8 , 10 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 23 </Td> <Td> Vanadium </Td> <Td> 2 , 8 , 11 , 2 </Td> <Td> 5 </Td> </Tr> <Tr> <Td> 24 </Td> <Td> Chromium </Td> <Td> 2 , 8 , 13 , 1 </Td> <Td> 6 </Td> </Tr> <Tr> <Td> 25 </Td> <Td> Manganese </Td> <Td> 2 , 8 , 13 , 2 </Td> <Td> 7 </Td> </Tr> <Tr> <Td> 26 </Td> <Td> Iron </Td> <Td> 2 , 8 , 14 , 2 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> 27 </Td> <Td> Cobalt </Td> <Td> 2 , 8 , 15 , 2 </Td> <Td> 9 </Td> </Tr> <Tr> <Td> 28 </Td> <Td> Nickel </Td> <Td> 2 , 8 , 16 , 2 </Td> <Td> 10 </Td> </Tr> <Tr> <Td> 29 </Td> <Td> Copper </Td> <Td> 2 , 8 , 18 , 1 </Td> <Td> 11 </Td> </Tr> <Tr> <Td> 30 </Td> <Td> Zinc </Td> <Td> 2 , 8 , 18 , 2 </Td> <Td> 12 </Td> </Tr> <Tr> <Td> 31 </Td> <Td> Gallium </Td> <Td> 2 , 8 , 18 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 32 </Td> <Td> Germanium </Td> <Td> 2 , 8 , 18 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 33 </Td> <Td> Arsenic </Td> <Td> 2 , 8 , 18 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 34 </Td> <Td> Selenium </Td> <Td> 2 , 8 , 18 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 35 </Td> <Td> Bromine </Td> <Td> 2 , 8 , 18 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 36 </Td> <Td> Krypton </Td> <Td> 2 , 8 , 18 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 37 </Td> <Td> Rubidium </Td> <Td> 2 , 8 , 18 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 38 </Td> <Td> Strontium </Td> <Td> 2 , 8 , 18 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 39 </Td> <Td> Yttrium </Td> <Td> 2 , 8 , 18 , 9 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 40 </Td> <Td> Zirconium </Td> <Td> 2 , 8 , 18 , 10 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 41 </Td> <Td> Niobium </Td> <Td> 2 , 8 , 18 , 12 , 1 </Td> <Td> 5 </Td> </Tr> <Tr> <Td> 42 </Td> <Td> Molybdenum </Td> <Td> 2 , 8 , 18 , 13 , 1 </Td> <Td> 6 </Td> </Tr> <Tr> <Td> 43 </Td> <Td> Technetium </Td> <Td>
<Table> <Tr> <Th> Z </Th> <Th> Element </Th> <Th> No. of electrons / shell </Th> <Th> Group </Th> </Tr> <Tr> <Td> </Td> <Td> Hydrogen </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Helium </Td> <Td> </Td> <Td> 18 </Td> </Tr> <Tr> <Td> </Td> <Td> Lithium </Td> <Td> 2 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Beryllium </Td> <Td> 2 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Boron </Td> <Td> 2 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Carbon </Td> <Td> 2 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Nitrogen </Td> <Td> 2 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Oxygen </Td> <Td> 2 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Fluorine </Td> <Td> 2 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Neon </Td> <Td> 2 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Sodium </Td> <Td> 2 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Magnesium </Td> <Td> 2 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 13 </Td> <Td> Aluminium </Td> <Td> 2 , 8 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 14 </Td> <Td> Silicon </Td> <Td> 2 , 8 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 15 </Td> <Td> Phosphorus </Td> <Td> 2 , 8 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 16 </Td> <Td> Sulfur </Td> <Td> 2 , 8 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 17 </Td> <Td> Chlorine </Td> <Td> 2 , 8 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 18 </Td> <Td> Argon </Td> <Td> 2 , 8 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 19 </Td> <Td> Potassium </Td> <Td> 2 , 8 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 20 </Td> <Td> Calcium </Td> <Td> 2 , 8 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 21 </Td> <Td> Scandium </Td> <Td> 2 , 8 , 9 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 22 </Td> <Td> Titanium </Td> <Td> 2 , 8 , 10 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 23 </Td> <Td> Vanadium </Td> <Td> 2 , 8 , 11 , 2 </Td> <Td> 5 </Td> </Tr> <Tr> <Td> 24 </Td> <Td> Chromium </Td> <Td> 2 , 8 , 13 , 1 </Td> <Td> 6 </Td> </Tr> <Tr> <Td> 25 </Td> <Td> Manganese </Td> <Td> 2 , 8 , 13 , 2 </Td> <Td> 7 </Td> </Tr> <Tr> <Td> 26 </Td> <Td> Iron </Td> <Td> 2 , 8 , 14 , 2 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> 27 </Td> <Td> Cobalt </Td> <Td> 2 , 8 , 15 , 2 </Td> <Td> 9 </Td> </Tr> <Tr> <Td> 28 </Td> <Td> Nickel </Td> <Td> 2 , 8 , 16 , 2 </Td> <Td> 10 </Td> </Tr> <Tr> <Td> 29 </Td> <Td> Copper </Td> <Td> 2 , 8 , 18 , 1 </Td> <Td> 11 </Td> </Tr> <Tr> <Td> 30 </Td> <Td> Zinc </Td> <Td> 2 , 8 , 18 , 2 </Td> <Td> 12 </Td> </Tr> <Tr> <Td> 31 </Td> <Td> Gallium </Td> <Td> 2 , 8 , 18 , 3 </Td> <Td> 13 </Td> </Tr> <Tr> <Td> 32 </Td> <Td> Germanium </Td> <Td> 2 , 8 , 18 , 4 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> 33 </Td> <Td> Arsenic </Td> <Td> 2 , 8 , 18 , 5 </Td> <Td> 15 </Td> </Tr> <Tr> <Td> 34 </Td> <Td> Selenium </Td> <Td> 2 , 8 , 18 , 6 </Td> <Td> 16 </Td> </Tr> <Tr> <Td> 35 </Td> <Td> Bromine </Td> <Td> 2 , 8 , 18 , 7 </Td> <Td> 17 </Td> </Tr> <Tr> <Td> 36 </Td> <Td> Krypton </Td> <Td> 2 , 8 , 18 , 8 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 37 </Td> <Td> Rubidium </Td> <Td> 2 , 8 , 18 , 8 , 1 </Td> <Td> </Td> </Tr> <Tr> <Td> 38 </Td> <Td> Strontium </Td> <Td> 2 , 8 , 18 , 8 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 39 </Td> <Td> Yttrium </Td> <Td> 2 , 8 , 18 , 9 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 40 </Td> <Td> Zirconium </Td> <Td> 2 , 8 , 18 , 10 , 2 </Td> <Td> </Td> </Tr> <Tr> <Td> 41 </Td> <Td> Niobium </Td> <Td> 2 , 8 , 18 , 12 , 1 </Td> <Td> 5 </Td> </Tr> <Tr> <Td> 42 </Td> <Td> Molybdenum </Td> <Td> 2 , 8 , 18 , 13 , 1 </Td> <Td> 6 </Td> </Tr> <Tr> <Td> 43 </Td> <Td> Technetium </Td> <Td>
the number of electrons in the innermost shell of lithium ( atomic number 3 )
the number of electrons in the innermost shell of lithium ( atomic number 3 )
1
1