Which layer is at the center of the earth, and exists as a hot, dense ball of (mostly) iron?

If forces acting on an object are unbalanced. true or false

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

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)