What Is the Basic Difference Between Comets and Asteroids

question 114

Multiple Choice

What is the basic difference between comets and asteroids?

• A) Comets always move in open orbits around the Sun and hence visit the Sun only once in their lifetime, whereas asteroids move in closed orbits.
• B) Comets always emit their own light, whereas asteroids only reflect sunlight.
• C) Comets are spherical, whereas asteroids are mostly irregular in shape.
• D) Comets are mostly composed of roughly equal mixtures of rocks and ices, whereas asteroids are mainly composed of rocks.

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Definitions:

Radiotherapy

A treatment method that uses high-energy radiation, typically X-rays, gamma rays, or electrons, to damage or destroy cancer cells.

Cobalt Treatment

A form of radiotherapy using gamma rays from cobalt-60 to treat conditions such as cancer.

Radiation Absorbed Dose

A measure of the amount of radiation energy absorbed by an object or person, expressed in Grays (Gy).

Rad

An abbreviation for "radical," often used in chemistry to describe highly reactive molecules with unpaired electrons; colloquially, used to express that something is excellent or cool.