Which of the following statements are TRUE about nonmetals? SELECT ALL THAT APPLY
a They can exist as solids, liquids, or gases
b
They have a wide variety of properties, most of
which are the opposite of metals.
С
They tend to have higher melting points than
metals.
d
They make up the majority of the periodic table of
elements

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)