A hydrated salt, compound A, is analysed and has the following percentage composition by mass; Cr, 19.51%;

Cl, 39.96%;

H, 4.51%;

O, 36.02%

Calculate the formula of compound A, showing clearly the water of crystallisation.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Determine the reaction and balance the following equations urgent due in the morning

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory