A photon has 8.0 × 10–15 J of energy. Planck’s constant is 6.63 × 10–34 J•s. What is the frequency of the photon?

1.21 × 1019 Hz
8.3 × 10–20 Hz
1.21 × 10–19 Hz
8.3 × 1020 Hz

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

In 2002, the rare earth elements mine in mountain pass, california was closed because