Element 1 has 1 valence electron, element 2 has 2 valence electrons, element 3 has 3 valence electrons, element 4 has 4 valence electrons, which is the least reactive? a. element 1 b. element 2 c. element d. element 4

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

fe 55.85 g/mol and h2o 18.02 g/mol.

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.