Differentiate between Lanthanoids and Actinoids

Lanthanoids and Actinoids are two series of elements in the periodic table. Lanthanoids (elements 57-71) belong to the f-block and are known for their shiny, soft metals, often used in magnets and lasers. Actinoids (elements 89-103) are radioactive, with some used in nuclear energy. Both series fill the 4f and 5f orbitals, respectively. Keep reading to learn how to differentiate between Lanthanoids and Actinoids.

Complete Answer:

Lanthanoids and Actinoids are f-block elements, but they differ in key aspects. Lanthanoids (elements 57-71) involve the filling of 4f orbitals, are mostly non-radioactive, and show limited oxidation states (+3 being common). They are used in magnets, phosphors, and catalysts. Actinoids (elements 89-103) involve 5f orbital filling, are all radioactive, and exhibit variable oxidation states (+3, +4, +5, etc.). While lanthanoids occur naturally, most actinoids are synthetic and are used in nuclear energy and medicine.

Here is how to differentiate between Lanthanoids and Actinoids:

Lanthanoids	Actinoids
The atomic numbers of Lanthanoid elements range from 57 to 71. Here is list of Lanthanoids: Lanthanum (La) – 57 Cerium (Ce) – 58 Praseodymium (Pr) – 59 Neodymium (Nd) – 60 Promethium (Pm) – 61 Samarium (Sm) – 62 Europium (Eu) – 63 Gadolinium (Gd) – 64 Terbium (Tb) – 65 Dysprosium (Dy) – 66 Holmium (Ho) – 67 Erbium (Er) – 68 Thulium (Tm) – 69 Ytterbium (Yb) – 70 Lutetium (Lu) – 71	The atomic numbers of Lanthanoid elements range from 89 to 103. Here is a list of Actinoids: Actinium (Ac) – 89 Thorium (Th) – 90 Protactinium (Pa) – 91 Uranium (U) – 92 Neptunium (Np) – 93 Plutonium (Pu) – 94 Americium (Am) – 95 Curium (Cm) – 96 Berkelium (Bk) – 97 Californium (Cf) – 98 Einsteinium (Es) – 99 Fermium (Fm) – 100 Mendelevium (Md) – 101 Nobelium (No) – 102 Lawrencium (Lr) – 103
These elements fill the 4f orbitals progressively.	These elements fill the 5f orbitals progressively.
Most lanthanoids are non-radioactive, except for a few isotopes.	All actinoids are radioactive.
Lanthanoids are found in the Earth’s crust.	Most of the Actinoids; except elements like uranium, thorium, etc; are synthetic.
These elements have a common oxidation state of +3, with limited variability.	These elements show variable oxidation states (+3, +4, +5, etc.).
Lantanoids are less reactive than actinoids. Their reactivity increases with atomic number.	Actinoids are highly reactive, especially with oxygen and halogens.
Lanthanoid elements are usually harder and have higher melting points than actinoids.	Actinoids are softer and have relatively lower melting points than Lanthanoids.
These elements show strong paramagnetism.	These elements are paramagnetic but influenced by radioactive properties.
Lanthanoids are used in magnets, phosphors, and catalysts.	Actinoids are used in nuclear reactors, weapons, and medicine.

Interesting Facts about Lanthanoids and Actinoids

Here are some interesting facts about Lanthanoids:

• Lanthanoids are often called “rare earth metals” and have a silvery appearance, but they tarnish quickly in air.
• Lanthanoids like Neodymium (Nd) are used to make powerful magnets found in electric motors and headphones.
• Europium (Eu) and Terbium (Tb) are used in phosphors for TV screens and fluorescent lights.
• Promethium (Pm) is the only lanthanoid that does not occur naturally and is produced in nuclear reactors.
• Lanthanoids are highly reactive with water and acids, releasing hydrogen gas.

Here are some interesting facts about Actinoids:

• All actinoids are radioactive, and many are highly unstable, decaying into other elements.
• Uranium (U) and Plutonium (Pu) are critical in nuclear power and weapons development.
• Most actinoids, like Americium (Am) and Curium (Cm), are synthetic and do not exist naturally.
• Actinium (Ac) is used in cancer treatments due to its radioactive properties.
• Actinoids react readily with oxygen, halogens, and acids, forming a variety of compounds.

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