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What are Lanthanoids? |
14 elements in the VI period (atomic number = 58 to 71) that are filling the 4f-sublevel 14 elements in the VII period (atomic number = 50 to 71) that are filling the 4f-sublevel 14 elements in the VII period (atomic number = 90 to 103) that are filling the 5f-sublevel 14 elements in the VI period (atomic number = 90 to 103) that are filling the 4f-sublevel |
14 elements in the VI period (atomic number = 58 to 71) that are filling the 4f-sublevel |
The answer is (1), 14 elements in the VI period (atomic number = 58 to 71) that are filling the 4f-sublevel. Lanthanides are a group of 15 chemical elements with atomic numbers 57 to 71. They are all in the sixth period of the periodic table, and they have a partially filled 4f subshell. The lanthanides are often called rare earth elements, but they are not particularly rare. The other answer choices are incorrect. Option (2) is incorrect because the lanthanides are in the sixth period, not the seventh period. Option (3) is incorrect because the lanthanides are filling the 4f subshell, not the 5f subshell. Option (4) is incorrect because the lanthanides have atomic numbers from 57 to 71, not 90 to 103. |
