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Which of the following elements is not a Noble gas?
Explanation
Noble gases are a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The naturally occurring noble gases are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn). They are located in Group 18 of the periodic table.
Actinium (Ac), with atomic number 89, is a silvery-white radioactive metallic element. It is the first element of the actinide series (Group 3) and is not a noble gas. Therefore, option D is the correct answer.
SIMILAR QUESTIONS
Which one of the following statements about the noble gases is not correct ?
Consider the following statements in respect of noble gases :
I. They are p-block elements.
II. They are highly active.
III. They have completely filled electronic configurations.
Which of the statements given above is/are correct?