{"id":331,"date":"2020-04-09T10:50:19","date_gmt":"2020-04-09T10:50:19","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=331"},"modified":"2023-08-15T11:28:23","modified_gmt":"2023-08-15T11:28:23","slug":"actinium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/actinium\/","title":{"rendered":"Actinium (Ac)"},"content":{"rendered":"\n

Actinium<\/b> is a rare-earth element that belongs to the family of <\/span>actinides <\/b>in the periodic table<\/a>. 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.\u00a0<\/span><\/p>\n\n\n\n

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Physical and Chemical Properties of Actinium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
The symbol in the periodic table of elements<\/td>Ac<\/td><\/tr>
Atomic number<\/td>89<\/td><\/tr>
Atomic weight (mass)<\/td>227 g.mol-1<\/td><\/tr>
Group number<\/td>3<\/td><\/tr>
Period<\/td>7<\/td><\/tr>
Color<\/td>Silvery-white<\/td><\/tr>
Physical state<\/td>A radioactive metal<\/td><\/tr>
Electronegativity according to Pauling<\/td>1.1<\/td><\/tr>
Density<\/td>10.07 g.cm-3 at 20\u00b0C<\/td><\/tr>
Melting point<\/td>1050 \u00b0C<\/td><\/tr>
Boiling point<\/td>3250 \u00b0C<\/td><\/tr>
Van der Waals radius<\/td>Unknown<\/td><\/tr>
Ionic radius<\/td>Unknown<\/td><\/tr>
Isotopes<\/td>4<\/td><\/tr>
Electronic shell<\/td>[ Rn ] 6d1 7s2<\/td><\/tr>
The energy of first ionization<\/td>664.6 kJ.mol-1<\/td><\/tr>
The energy of second ionization<\/td>1165.5 kJ.mol-1<\/td><\/tr>
Discovery date<\/td>In 1899 (1902), by Andr\u00e9 Debierne<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

With the periodic table symbol Ac, atomic number 89, atomic mass of 227 g.mol -1, and electronic configuration [Rn] 6d17s2, actinium reaches its boiling point at 3250 \u00b0C, while the melting point is achieved at 1050 \u00b0C. This member of the actinide family of elements in the periodic table has an electronegativity of 1.1 according to Pauling, whereas the atomic radius according to van der Waals is unknown. <\/span><\/p>\n\n\n\n

Actinium displays an oxidation state of +3, which is a chemical property related to lanthanum<\/a>. The powerful radioactive properties of actinium give this element its most notable physical characteristic – the pale blue glow in the dark. But, it\u2019s not the substance that emits the blue light. <\/span><\/p>\n\n\n\n

Since actinium is way more radioactive than radium<\/a>, it emits an enormous quantity of electrons that stimulate oxygen molecules in the surrounding air. The energy released by the ionized oxygen<\/a> appears as a pale blue glow from the radioactive substance.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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How Was Actinium Discovered?<\/span><\/h2>\n\n\n\n

The French chemist Andr\u00e9-Louis Debierne (14 July 1874, Paris, France – 31 August 1949, Paris, France) is the first scientist who discovered this periodic table element. Debierne managed to isolate actinium by exploring a <\/span>pitchblende<\/span><\/i>, i.e., remainders of uranium<\/a> ore (uranium oxide, U3O8) from the experiments on radium carried out by the Nobel-winning chemists Marie Curie<\/a> and Pierre Curie. <\/span><\/p>\n\n\n\n

According to the findings of the French chemist, Debierne, the newly-discovered substance named actinium shares the chemical properties of titanium<\/a> and thorium. This discovery took place in 1899, while Debierne was trying to separate rare earth oxides.\u00a0<\/span><\/p>\n\n\n\n

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How Did Actinium Get Its Name?<\/span><\/h2>\n\n\n\n

Three years later, after Debierne discovered actinium, Friedrich Oskar Giesel ( 20 May 1852, <\/span>Winzig, Germany – 13 November 1927, Braunschweig, Germany) <\/span>discovered this element while conducting his scientific research, without knowing that it had already been discovered. His results showed similarities between actinium and lanthanum. In 1904, Giesel labeled the new element as \u201cemanium\u201d. <\/span><\/p>\n\n\n\n

Since there were two independent discoveries of the same chemical element, several other scientists compared Debierne and Giesel\u2019s research. In the 1970s, the first Canadian female nuclear physicist and two German chemists (Harriet Brooks, Otto Hahn, and Otto Sackur) comprised the scientific research team that confirmed the chemical properties of the new substance and decided to keep its first name. In this way, Debierne holds the honor of being the first chemist to discover <\/span>actinium<\/b>.\u00a0<\/span><\/p>\n\n\n\n

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Where Can You Find Actinium?<\/span><\/h2>\n\n\n\n

Actinium can be found in microscopic traces in uranium or thorium<\/a> ore. Only 0.15 mg of actinium can be found in a tone of pitchblende ore. Due to its scarcity, this chemical element is often produced in labs. Its production is costly and dangerous, so the application of actinium is limited to scientific, energetic, and medical uses, such as in nuclear reactors, radiation therapy, etc.<\/span><\/p>\n\n\n\n

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Nuclear Medicine (Radiation Therapy)<\/span><\/h3>\n\n\n\n

Nuclear medicine<\/b> is a biology branch that uses small doses of radioactive substances to examine and treat malignant (cancerous) tumors. By implementing <\/span>radiation therapy<\/b> (or radiotherapy) in the treatments, nuclear medicine utilizes the high intensity of the radioactive beams to destroy malignant tumor cells. More specifically, actinium-255 (Ac-255) isotope with a half-life of 10 days is used in the treatment of cancer patients. This type of radiation therapy is typically performed via extremely short electromagnetic waves of high energy. <\/span><\/p>\n\n\n\n

These high-energy waves are produced in a special machine that radiates the beams precisely onto the tumorous lump formed on a particular tissue. The beams protrude the mutated neuron cell\u2019s body and destroy the genetic material they carry. That\u2019s how radiation therapy controls or completely stops the multiplication and growth of cancerous cells in the body.\u00a0<\/span><\/p>\n\n\n\n

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Spacecraft Power Systems<\/span><\/h3>\n\n\n\n

Since there are no gas stations for spacecraft in space, the production of neutrons is the only solution for fueling the vehicles that are on a mission of exploring the Solar System. <\/span><\/p>\n\n\n\n

Due to the high activity level of actinium, spacecraft power systems use the radioisotope power and neutron irradiation that is generated by the radioactive elements. When actinium (or any other radioactive element) breaks down, it generates heat that is used by these power systems as a source of energy.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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Nuclear Power Reactors<\/span><\/h3>\n\n\n\n

A nuclear power reactor is a machine that generates electricity by splitting the atoms of particular chemical elements apart and producing neutrons by a controlled nuclear reaction. That\u2019s why radioactive elements are used as fuel.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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How Dangerous Is Actinium?<\/span><\/h2>\n\n\n\n

Actinium imposes enormous health hazards due to its intense radioactivity. Despite being used to cure cancer and heal the body\u2019s tissues, healthy cells are also destroyed alongside tumorous cells during radiation therapy in cancer patients. The body reacts to the destruction of healthy cells due to radioactivity exposure by triggering:<\/span><\/p>\n\n\n\n