Which of the following is an extremely reactive family of elements?
a noble gases
C carbon family
b. halogens
& metalloids
Please select the best answer from the choices provided

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)

What was the purpose of the apollo program? to put a man in orbit to launch a spy satellite to launch a space station to put man on the moon

The largest observatory complex in the world is on mauna kea, the tallest mountain on earth. what are some factors astronomers consider when selecting an observatory site? don’t forget practical ones. should astronomers, for example, consider building an observatory on denali (mount mckinley) or mount everest?