How Do We Know That Galaxy Clusters Contain a Lot

question 70

Multiple Choice

How do we know that galaxy clusters contain a lot of mass in the form of hot gas that fills spaces between individual galaxies?

• A)We detect this gas with X- ray telescopes.
• B)We infer its existence by observing its gravitational effects on the galaxy motions.
• C)The hot gas shows up as bright pink in visible- light photos of galaxy clusters.
• D)We can observe the frictional effects of the hot gas in slowing the speeds of galaxies in the clusters.

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Definitions:

Cognitive Development

The process of growth and change in intellectual/mental abilities such as thinking, reasoning, and understanding over the course of a person's life.

Piaget

A Swiss developmental psychologist and philosopher known for his pioneering work in child development and his theory of cognitive development in children.

Symbolic Thinking

The ability to use symbols, signs, or objects to represent ideas or concepts, significant in language development and creative thinking.

Cognitive Developmental Milestones

Refer to the key stages in early childhood and adolescence where individuals achieve new abilities in language, thought, problem-solving, and personal interaction.