Chemical element List of the 118 known chemical elements List of the 118 known chemical elements

| Atomic_no_ | Name_ | Symbol | Group_ | Period | Block | State_at_STP | Occurrence | Description_ |
|---|---|---|---|---|---|---|---|---|
| 33 | Arsenic | As | 15 | 4 | p | Solid | Primordial | Metalloid |
| 34 | Selenium | Se | 16 | 4 | p | Solid | Primordial | Non-metal |
| 35 | Bromine | Br | 17 | 4 | p | Liquid | Primordial | Halogen |
| 36 | Krypton | Kr | 18 | 4 | p | Gas | Primordial | Noble gas |
| 37 | Rubidium | Rb | 1 | 5 | s | Solid | Primordial | Alkali metal |
| 38 | Strontium | Sr | 2 | 5 | s | Solid | Primordial | Alkaline earth metal |
| 39 | Yttrium | Y | 3 | 5 | d | Solid | Primordial | Transition metal |
| 40 | Zirconium | Zr | 4 | 5 | d | Solid | Primordial | Transition metal |
| 41 | Niobium | Nb | 5 | 5 | d | Solid | Primordial | Transition metal |
| 42 | Molybdenum | Mo | 6 | 5 | d | Solid | Primordial | Transition metal |
| 43 | Technetium | Tc | 7 | 5 | d | Solid | Transient | Transition metal |