A Crystal with a Well-Defined Shape, Such as a Cube

question 69

Multiple Choice

A crystal with a well-defined shape, such as a cube, probably:

• A) does not reflect the arrangement of atoms in the lattice
• B) grew early and so was forced to grow around other minerals
• C) does not have a well-defined cleavage
• D) will react with dilute hydrochloric acid
• E) none of these

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Definitions:

The Retina

A layer at the back of the eye that contains cells sensitive to light and triggers nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.

Optic Nerve

The structure at the back of the eye, made up of axons of the ganglion cells, that carries visual information to the brain for further processing.

Blind Spot

An area in the visual field that lacks light-detecting photoreceptor cells on the optic disc of the retina, making it insensitive to light.

The Retina

The retina is a layer of tissue at the back of the eye that senses light and sends signals to the brain, enabling visual perception.