Encyclopedic Guide to the Periodic Table of Elements

Hydrogen

(H): Atomic number $1$, Atomic weight $1.0078$. Category: Other nonmetals.

Helium

(He): Atomic number $2$, Atomic weight $4.0026$. Category: Noble gases.

Lithium

(Li): Atomic number $3$, Atomic weight $6.938$. Category: Alkalai metals.

Beryllium

(Be): Atomic number $4$, Atomic weight $9.0122$. Category: Alkaline earth metals.

Boron

(B): Atomic number $5$, Atomic weight $10.806$. Category: Metalloids.

Carbon

(C): Atomic number $6$, Atomic weight $12.009$. Category: Other nonmetals.

Nitrogen

(N): Atomic number $7$, Atomic weight $14.006$. Category: Other nonmetals.

Oxygen

(O): Atomic number $8$, Atomic weight $15.999$. Category: Other nonmetals.

Fluorine

(F): Atomic number $9$, Atomic weight $18.998$. Category: Halogens.

Neon

(Ne): Atomic number $10$, Atomic weight $20.180$. Category: Noble gases.

Sodium

(Na): Atomic number $11$, Atomic weight $22.990$. Category: Alkalai metals.

Magnesium

(Mg): Atomic number $12$, Atomic weight $24.305$. Category: Alkaline earth metals.

Aluminum

(Al): Atomic number $13$, Atomic weight $26.982$. Category: Post-transition metals.

Silicon (Si): Atomic number $14$, Atomic weight $28.084$. Category: Metalloids.

Phosphorus (P): Atomic number $15$, Atomic weight $30.974$. Category: Other nonmetals.

Sulfur (S): Atomic number $16$, Atomic weight $32.059$. Category: Other nonmetals.

Chlorine (Cl): Atomic number $17$, Atomic weight $35.446$. Category: Halogens.

Argon (Ar): Atomic number $18$, Atomic weight $39.948$. Category: Noble gases.

Potassium (K): Atomic number $19$, Atomic weight $39.098$. Category: Alkalai metals.

Calcium (Ca): Atomic number $20$, Atomic weight $40.078$. Category: Alkaline earth metals.

Scandium (Sc): Atomic number $21$, Atomic weight $44.956$. Category: Transition metals.

Titanium (Ti): Atomic number $22$, Atomic weight $47.867$. Category: Transition metals.

Vanadium (V): Atomic number $23$, Atomic weight $50.942$. Category: Transition metals.

Chromium (Cr): Atomic number $24$, Atomic weight $51.996$. Category: Transition metals.

Manganese (Mn): Atomic number $25$, Atomic weight $54.938$. Category: Transition metals.

Iron (Fe): Atomic number $26$, Atomic weight $55.845$. Category: Transition metals.

Cobalt (Co): Atomic number $27$, Atomic weight $58.933$. Category: Transition metals.

Nickel (Ni): Atomic number $28$, Atomic weight $58.693$. Category: Transition metals.

Copper (Cu): Atomic number $29$, Atomic weight $63.546$. Category: Transition metals.

Zinc (Zn): Atomic number $30$, Atomic weight $65.38$. Category: Transition metals.

Gallium (Ga): Atomic number $31$, Atomic weight $69.723$. Category: Post-transition metals.

Germanium (Ge): Atomic number $32$, Atomic weight $72.63$. Category: Metalloids.

Arsenic (As): Atomic number $33$, Atomic weight $74.922$. Category: Metalloids.

Selenium (Se): Atomic number $34$, Atomic weight $78.96$. Category: Other nonmetals.