If humans can't see air but can see water, does it mean that fish can see air but can't see water?

Which statement about covalent bonds is true

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

Two rigid transformations are used to map δhjk to δlmn. the first is a translation of vertex h to vertex l. what is the second transformation? a reflection across the line containing hk a rotation about point h a reflection across the line containing hj a rotation about point k