| # | Symbol | Name | Atomic Mass | Category |
|---|---|---|---|---|
| 19 | K | Potassium | 39.098 | Alkali Metals |
| 20 | Ca | Calcium | 40.078 | Alkaline Earth Metals |
| 21 | Sc | Scandium | 44.956 | Transition Metals |
| 22 | Ti | Titanium | 47.867 | Transition Metals |
| 23 | V | Vanadium | 50.942 | Transition Metals |
| 24 | Cr | Chromium | 51.996 | Transition Metals |
| 25 | Mn | Manganese | 54.938 | Transition Metals |
| 26 | Fe | Iron | 55.845 | Transition Metals |
| 27 | Co | Cobalt | 58.933 | Transition Metals |
| 28 | Ni | Nickel | 58.693 | Transition Metals |
| 29 | Cu | Copper | 63.546 | Transition Metals |
| 30 | Zn | Zinc | 65.38 | Transition Metals |
| 31 | Ga | Gallium | 69.723 | Post-Transition Metals |
| 32 | Ge | Germanium | 72.63 | Metalloids |
| 33 | As | Arsenic | 74.922 | Metalloids |
| 34 | Se | Selenium | 78.971 | Other Non-Metals |
| 35 | Br | Bromine | 79.904 | Halogens |
| 36 | Kr | Krypton | 83.798 | Noble Gases |
18 elements