Question

Match the events related to the formation of the universe with the stages during which they occurred.

1) The first neutral atoms begin to form.
2) Hydrogen fuses into helium.
3) Expansion from an infinitely hot point.

Answer 1

The events related to the formation of the universe can be matched with the stages during which they occurred: expansion from an infinitely hot point, hydrogen fuses into helium, and the first neutral atoms begin to form.

Step-by-step explanation:

The events related to the formation of the universe can be matched with the stages during which they occurred as follows:

1. Expansion from an infinitely hot point: This event occurred at the very beginning of the universe when it started expanding from an infinitely hot and dense state.
2. Hydrogen fuses into helium: This event happened after the expansion, when the universe was about 3-4 minutes old and the temperature was around 900 million K. At this stage, hydrogen nuclei fused to form helium and a small amount of lithium.
3. The first neutral atoms begin to form: This event occurred later in the universe's history, after it had expanded and cooled down enough for electrons to combine with nuclei, forming neutral atoms.