How is the word theory as it is used in science different from the common use of the word outside of science?

100mg magnesium reacts with 20ml of 1.0m hcl

Of the groups of elements below, which are most likely to gain electrons to become anions? a. alkali metal b. boron group c. halogen d. transition metal

As you watch a surfer ride a wave towards the shoreline, what is the shoreline? a) displacement reference b) reference point c) coordinate plane d) cartesian boundary