What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s)

2.9817 x 10-40 joules

4.4143 x 10-19 joules

6.6745 x 10-26 joules second

9.9456 x 10-49 joules

19.864 x 10-26 joules/second

=force × distance a. work b. velocity c. pressure d. momentum

Iron is a transition metal with multiple oxidation numbers. (answer the following) a. what is the iron (ii) ion? how does it differ from the iron (iii) ion? b. if iron were to bond with oxygen, predict the formula for each oxidation number of iron. c. how would each formula be named?

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)