A proton is placed at a distance of 5.3 × 10-11 m. from an electron. Calculate the electrostatic force between them and determine the polarity. (Proton charge = 1.6 × 10-19 C. Electron charge = -1. 6 × 10-19 C).

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

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.

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same