| 释义 |
Definition of actinium in English: actiniumnoun akˈtɪnɪəmækˈtɪniəm mass nounThe chemical element of atomic number 89, a radioactive metallic element of the actinide series. It is rare in nature, occurring as an impurity in uranium ores. Example sentencesExamples - The first four actinide elements, actinium, thorium, protactinium and uranium are naturally occurring and have been known for a considerable time.
- Along the way, these disintegration series produce radioactive isotopes of protactinium, thorium, actinium, radium, francium, radon, astatine, polonium, bismuth, lead, thallium and mercury.
- Francium was discovered in 1939 by the French physicist Marguerite Perey while she was analyzing the products formed during the radioactive decay of actinium.
- A proposal was patented for a ceramic block pessary using radioactive elements such as thorium, actinium and even radium.
- Actinides - the radioactive chemical elements that span from actinium to lawrencium on the periodic table - have generated a great deal of interest in recent years.
Origin Early 20th century: from Greek aktis, aktin- 'ray' + -ium. Rhymes aluminium, condominium, delphinium Definition of actinium in US English: actiniumnounakˈtinēəmækˈtɪniəm The chemical element of atomic number 89, a radioactive metallic element of the actinide series. It is rare in nature, occurring as an impurity in uranium ores. Example sentencesExamples - Actinides - the radioactive chemical elements that span from actinium to lawrencium on the periodic table - have generated a great deal of interest in recent years.
- A proposal was patented for a ceramic block pessary using radioactive elements such as thorium, actinium and even radium.
- Francium was discovered in 1939 by the French physicist Marguerite Perey while she was analyzing the products formed during the radioactive decay of actinium.
- Along the way, these disintegration series produce radioactive isotopes of protactinium, thorium, actinium, radium, francium, radon, astatine, polonium, bismuth, lead, thallium and mercury.
- The first four actinide elements, actinium, thorium, protactinium and uranium are naturally occurring and have been known for a considerable time.
Origin Early 20th century: from Greek aktis, aktin- ‘ray’ + -ium. |