Coal Can Be Cleaned Before It Is Burned

question 128

Multiple Choice

Coal can be cleaned before it is burned.The flotation method separates coal from its major impurities by taking advantage of the difference in ________ of these materials.

• A)acidity
• B)combustion
• C)density
• D)volatility

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Definitions:

Hemianopia

A vision disorder characterized by a loss of vision or blindness in half the visual field, usually resulting from damage to the brain or optic pathways.

Macula Lutea

A small, yellowish central area of the retina that is rich in cones and where visual acuity is highest.

Fovea Centralis

A small depression in the retina where visual acuity is highest.

Optic Disk

The spot in the eye where the optic nerve meets the retina, sometimes referred to as the blind spot.