At an Age of 380,000 Years, the Temperature of the Universe

question 173

Multiple Choice

At an age of 380,000 years, the temperature of the universe had fallen to 3000 K, and electrons could then combine with protons to produce neutral hydrogen gas. What major transition took place in the universe at this time?

• A) The present laws of physics began to apply for the first time.
• B) The universe suddenly lost its electrical charge and became neutral.
• C) Nuclear fusion no longer occurred below this temperature.
• D) The universe became transparent to light for the first time.

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Definitions:

Price Elasticity

The measure of how much the quantity demanded of a good responds to a change in the price of that good, expressing the sensitivity of demand to price changes.

Price Elasticity

An evaluation of how shifts in a good's price affect the quantity of it demanded.

Slope

In mathematics, the rate at which a line or curve inclines or declines, calculated as the ratio of the vertical change to the horizontal change between two points on the line.

Demand Curve

A graph showing the relationship between the price of a product and the quantity of the product that consumers are willing and able to purchase at various prices.