What are some indicators that a chemical reaction is occurring? check all that apply.

the formation of bubbles

a change in size

a change in color

the formation of a liquid

the formation of a precipitate

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87

How many neutrons does plutonium -196 with an atomic number of 78.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.