| 锕 | [ā, ㄚ, 锕 / 錒] actinium Ac89, actinoid element |
| 锕系元素 | [ā xì yuán sù, ㄚ ㄒㄧˋ ㄩㄢˊ ㄙㄨˋ, 锕系元素 / 錒系元素] actinoids (rare earth series), namely: actinium Ac89 錒|锕, thorium Th90 釷|钍, protoactinium Pa91 鏷|镤, uranium U92 鈾|铀, neptunium Ne93 镎|镎, plutonium Pu94 鈈|钚, americium Am95 镅|镅, curium Cm96 鋦|锔, berkelium Bk97 錇|锫, californium Cf98 鐦|锎, einsteinium Es99 鎄| |
| 镅 | [méi, ㄇㄟˊ, 镅] americium Am95, actinoid element |
| 锫 | [péi, ㄆㄟˊ, 锫 / 錇] berkelium Bk97, actinoid element |
| 锔 | [jú, ㄐㄩˊ, 锔 / 鋦] curium Cm96, radioactive actinoid element |
| 锿 | [āi, ㄞ, 锿 / 鎄] einsteinium Es99, radioactive actinoid element |
| 镄 | [fèi, ㄈㄟˋ, 镄 / 鐨] fermium Fm100, radioactive actinoid element |
| 钔 | [mén, ㄇㄣˊ, 钔 / 鍆] mendelevium Md101, radioactive actinoid element |
| 镎 | [ná, ㄋㄚˊ, 镎] neptunium Ne93, actinoid element |
| 锘 | [nuò, ㄋㄨㄛˋ, 锘 / 鍩] nobelium No102, radioactive actinoid element |
| 钚 | [bù, ㄅㄨˋ, 钚 / 鈈] plutonium Pu94, radioactive actinoid element |
| 镤 | [pú, ㄆㄨˊ, 镤 / 鏷] protoactinium Pa91, actinoid element |
| 钍 | [tǔ, ㄊㄨˇ, 钍 / 釷] thorium Th90, actinoid element |
| 铀 | [yóu, ㄧㄡˊ, 铀 / 鈾] uranium U92, actinoid element |