Actinium is a chemical element; it has symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in …

Purified actinium comes into equilibrium with its decay products at the end of 185 days, and then decays according to its 21.6-year half-life. It is about 150 times as active as radium, making it of value in the production of neutrons.

錒 ā （英語： Actinium），是一種 化學元素，其 化學符號 为 Ac， 原子序數 为89，位居 錒系元素 之首。 在 元素週期表 中，錒系元素始於錒，止於 鐒，一共有15種元素。 錒是一種柔軟的銀白色 金屬，具強 放射性。 錒屬於十分活潑的金屬，在空氣中會迅速與 氧氣 和 水氣 反應，在表面形成具保護性的白色氧化層。 和大部份 鑭系元素 及重錒系元素一樣，錒最常見的 氧化態 是+3，化學性質也和鑭系元素十分相似。 錒在1899年被發現，是首個得到分離的非 原始元素。 雖然 釙 …

2023年10月16日 · Actinium is a metal with qualities comparable to lanthanum, the element just above it on the periodic table. Ac has an atomic number of 89. It has a melting point of 1227 °C ( 2240 °F) (estimated) and a boiling point of 3200±300 °C ( 5800±500 °F) (extrapolated). Ac has a solid phase density of 10.07 g/cm 3 near room temperature.

2025年1月21日 · Actinium is a soft, silvery-white radioactive metallic element that showcases unique properties and specialized applications, with the atomic number 89. Actinium is known for its strong radioactivity, making it stand out among elements.

Actinium is chemical element 89 on the periodic table. Its symbol is Ac. Actinium's mass is 227 g/mol. Actinium is a silver radioactive, solid metal in actinide group. It is so radioactive that it glows in the dark. Even a small amount of actinium is dangerous to people. Actinium was discovered in 1899 by André-Louis Debierne, a French chemist.

2022年8月27日 · Actinium is a soft, silvery-white, radioactive, metallic element which glows in the dark with a pale-blue light. The atomic mass of actinium is 227. The melting point of actinium is 1050°C. The boiling point of actinium is 3250°C. The density of …

A radioactive metal, actinium (pronounced as ak-TIN-ee-em) belongs to the family of actinide metals and denoted by the chemical symbol Ac [1]. It has 29 isotopes out of which actinium-227 is the most stable one, having a half-life of 21.17 years. After which, it either undergoes alpha decay into francium-223, or beta decay into thorium-227 [3].

Pure actinium forms a silvery-white metal that has a face-centered structure near its melting point. In 1945 Glenn Seaborg proposed that actinium was the first member of a family of fifteen elements (the "actinides"), characterized by the possession of the 5 f orbitals.

2020年4月9日 · Actinium is a rare-earth element that belongs to the family of actinides in the periodic table. The actinide series of elements is highly significant due to their radioactive properties. They comprise a group of 15 chemical elements that share the same chemical and physical properties.