Group 7a of the periodic table contains the?
1. most reactive nonmetals
2. most reactive metals
3.least reactive nonmetals
4. least reactive metals

The inside surface of a cylindrical-shaped cave of inner diameter 1.0 m is continuously covered with a very thin layer of water. the cave is very long and it is open on both ends. the water on the cave surface is at a constant temperature of 15.5 °c. the cave is constantly exposed to wind such that 15.5 °c air flows through the cave at 4.5 m/s. the kinematic viscosity of the air is 14.66 x 10-6 m2/s and the molecular diffusion coefficient of water vapor in the air is 0.239 x 10-4 m2/s. because the cave diameter is so large, the flow of wind down the length of the cave, in the x direction, can be treated like it is external flow and the cave surface can be approximated as flat where appropriate. calculate the x value, in a) the transition to turbulent flow occurs at rex meters, where the air flow transitions from laminar to turbulent along the inside surface of the cave b) calculate the x value, in meters, where the bulk steady state concentration of water vapor in the air flowing in the cave is 10% of the saturation concentration. assume the air at the surface of the water layer is 100% saturated with water vapor. assume the wind entering the cave contained no moisture before it entered the cave. take into account the transition from laminar to turbulent flow when solving part b

Athird point charge q3 is now positioned halfway between q1 and q2. the net force on q2 now has a magnitude of f2,net = 5.861 n and points away from q1 and q3. what is the value (sign and magnitude) of the charge q3?

Determine the time it takes for a satellite to orbit the earth in a circular "near-earth" orbit. the definition of "near-earth" orbit is one which is at a height above the surface of the earth which is small compared to the radius of the earth, so that you may take the acceleration due to gravity as essentially the same as that on the surface. does your result depend on the mass of the satellite?