What is the mass percentage of Na in Na2S

Which of the following true? a_volcanoes and earthquakes often near the plate boundaries. b_volcanoes occur whereve there are tall mountains. c_earthquakes cause volcanoes in the same location to erupt violently d_volcanoes and earthquakes occur only where plates are colliding with each other

26. of of (aq) by (aq) is . if 50.00 ml of 1.05 m is to 25.00 ml of 1.86 m ,at be? ( no is toina of aof) , h.. (p. ). . .

An observation that requires measurement is called quantitative observable or qualitative