Which one of the following elements is a non-metal but is lustrous ?

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Q: (CDS-I/2021)

Which one of the following elements is a non-metal but is lustrous ?

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,27,42,3,15,24,27

keywords: 

{'germanium': [0, 0, 0, 1], 'elements': [0, 0, 2, 5], 'silicon': [0, 0, 1, 0], 'iodine': [2, 1, 1, 1], 'carbon': [1, 0, 4, 5]}

Out of the given options, option 4, Iodine, is the correct answer. Iodine is a non-metal but it is lustrous, which means it has a shiny or reflective appearance.

Option 1, Carbon, is a non-metal but it is not lustrous. Carbon is a dull solid in its most common form, graphite. Graphite is used in pencil leads and has a black, opaque appearance.

Option 2, Silicon, is a metalloid and not a non-metal. Metalloids have properties that are intermediate between metals and non-metals. Silicon is widely used in electronics and has a dull, metallic appearance.

Option 3, Germanium, is also a metalloid and not a non-metal. Germanium is used in semiconductors and has a shiny, metallic appearance similar to silicon.

Therefore, the correct answer is option 4, Iodine. It is a non-metal but exhibits a lustrous or shiny appearance.