High temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. Fusion requires temperatures of about 100 million Kelvin (approximately six times hotter than the sun's core).

Of the literary devices you provided to choose from, snap hots and thought shots are not even devices so they fall off the list.
sensory language can explain the senses the character is using - helping figure out his reflections,
but figuratve language can helop the best. the character says something figuratively and we can analyze what they meant to find out what they were thinking
The unit of height is:
Feet
Inches
Centimeters