What do scientists measure when determining the absolute age of a rock?

Idon’t understand this page, can someone ?

Which molecules are more strongly attracted to one another -c3h8o molecules that make up liquid rubbing alcohol or ch4 molecules that make up methane gas

If you try to move a piano and are unable to move it, did you perform any work in the scientific sense of the word? yes? or no? this question is worth 20 points! let it be correct!