The lanthanide series starts from and ends in which atomic number?

A. 55, 68

B. 56, 69

C. 57, 70

D. 58, 71

The lanthanide series is a fascinating group of elements in the periodic table, and it specifically consists of 15 elements that follow the element lanthanum. To answer your question, the lanthanide series starts with atomic number 57, which is lanthanum (La), and ends with atomic number 71, which is lutetium (Lu). Therefore, the correct option is C: 57, 70.

Understanding the Lanthanide Series

The lanthanides are often referred to as the "rare earth elements," and they include the following elements:

• Lanthanum (La) - Atomic number 57
• Cerium (Ce) - Atomic number 58
• Praseodymium (Pr) - Atomic number 59
• Neodymium (Nd) - Atomic number 60
• Promethium (Pm) - Atomic number 61
• Samarium (Sm) - Atomic number 62
• Europium (Eu) - Atomic number 63
• Gadolinium (Gd) - Atomic number 64
• Terbium (Tb) - Atomic number 65
• Dysprosium (Dy) - Atomic number 66
• Holmium (Ho) - Atomic number 67
• Erbium (Er) - Atomic number 68
• Thulium (Tm) - Atomic number 69
• Ytterbium (Yb) - Atomic number 70
• Lutetium (Lu) - Atomic number 71

Characteristics of Lanthanides

These elements share several common characteristics:

• Similar Chemical Properties: They often exhibit similar reactivity and oxidation states, primarily +3.
• High Magnetic Susceptibility: Many lanthanides are used in strong magnets and electronic devices.
• Colorful Compounds: Their compounds can produce vibrant colors, making them useful in phosphors for screens and lighting.

Applications of Lanthanides

Lanthanides have significant applications in various fields:

• Electronics: Used in the production of strong permanent magnets and phosphors in screens.
• Metallurgy: They improve the properties of metals when added as alloying agents.
• Medical Imaging: Certain lanthanides are used in MRI contrast agents.

In summary, the lanthanide series begins at atomic number 57 with lanthanum and concludes at atomic number 71 with lutetium. Their unique properties and applications make them an essential part of modern technology and industry.