Which of These Is Not a Metal

question 114

Multiple Choice

Which of these is not a metal?

• A)selenium (atomic no.= 34)
• B)gallium (atomic no.= 31)
• C)lithium (atomic no.= 3)
• D)potassium (atomic no.= 19)
• E)vanadium (atomic no.= 23)

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Definitions:

Lens

A transparent structure inside the eye that focuses light rays onto the retina to create clear images.

Aqueous Humor

A clear fluid filling the space in the front of the eyeball between the lens and the cornea, involved in nutrient supply and intraocular pressure maintenance.

Vitreous Humor

The clear, gel-like substance that fills the space between the lens and the retina in the eye, maintaining its shape.

Cornea

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, playing a key role in focusing visual images.