When using science to investigate physical phenomena, which of the following is NOT a characteristic of the event must exist?

measurable
falsifiable
observable
readable

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

What happens when the number of protons in an atom changes

The largest observatory complex in the world is on mauna kea, the tallest mountain on earth. what are some factors astronomers consider when selecting an observatory site? don’t forget practical ones. should astronomers, for example, consider building an observatory on denali (mount mckinley) or mount everest?