Hydrogen Helium Atomic number: 1 Atomic number: 2 Atomic weight: 1 H Atomic weight: 4 He State of matter: gas State of matter: gas Protons: 1 Protons: 2 Neutrons (usually): 0 Neutrons (usually): 2 Electrons: 1 Electrons: 2 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Lithium Beryllium Atomic number: 3 Atomic number: 4 Atomic weight: 7 Li Atomic weight: 9 Be State of matter: solid State of matter: solid Protons: 3 Protons: 4 Neutrons (usually): 4 Neutrons (usually): 5 Electrons: 3 Electrons: 4 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Boron Carbon Atomic number: 5 Atomic number: 6 Atomic weight: 11 B Atomic weight: 12 C State of matter: solid State of matter: solid Protons: 5 Protons: 6 Neutrons (usually): 6 Neutrons (usually): 6 Electrons: 5 Electrons: 6 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Nitrogen Oxygen Atomic number: 7 Atomic number: 8 Atomic weight: 14 N Atomic weight: 16 O State of matter: gas State of matter: gas Protons: 7 Protons: 8 Neutrons (usually): 7 Neutrons (usually): 8 Electrons: 7 Electrons: 8 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Fluorine Neon Atomic number: 9 Atomic number: 10 Atomic weight: 19 F Atomic weight: 20 Ne State of matter: gas State of matter: gas Protons: 9 Protons: 10 Neutrons (usually): 10 Neutrons (usually): 10 Electrons: 9 Electrons: 10 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Sodium Magnesium Atomic number: 11 Atomic number: 12 Atomic weight: 23 Na Atomic weight: 24 Mg State of matter: solid State of matter: solid Protons: 11 Protons: 12 Neutrons (usually): 12 Neutrons (usually): 12 Electrons: 11 Electrons: 12 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Aluminum Silicon Atomic number: 13 Atomic number: 14 Atomic weight: 27 Al Atomic weight: 28 Si State of matter: solid State of matter: solid Protons: 13 Protons: 14 Neutrons (usually): 14 Neutrons (usually): 14 Electrons: 13 Electrons: 14 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Phosphorus Sulfur Atomic number: 15 Atomic number: 16 Atomic weight: 31 P Atomic weight: 32 S State of matter: solid State of matter: solid Protons: 15 Protons: 16 Neutrons (usually): 16 Neutrons (usually): 16 Electrons: 15 Electrons: 16 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Chlorine Argon Atomic number: 17 Atomic number: 18 Atomic weight: 35 Cl Atomic weight: 40 Ar State of matter: gas State of matter: gas Protons: 17 Protons: 18 Neutrons (usually): 18 Neutrons (usually): 22 Electrons: 17 Electrons: 18 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com Potassium Calcium Atomic number: 19 Atomic number: 20 Atomic weight: 39 K Atomic weight: 40 Ca State of matter: solid State of matter: solid Protons: 19 Protons: 20 Neutrons (usually): 20 Neutrons (usually): 20 Electrons: 19 Electrons: 20 Number of Number of electron shells: electron shells: Number of Number of valence electrons: valence electrons: periodictable.rosendigital.com periodictable.rosendigital.com.