NASA detected a burst of gamma rays from a neutron star in space. The gamma radiation had a frequency of 1.0 × 1019 Hertz and the burst released a total of 1.0 × 1044 J of energy. How many moles of photons of gamma radiation were released during this burst?

1.51×10^58 moles of photons

Explanation:

n = E/hf

E is total energy = 1×10^44 J

h is Planck's constant = 6.634×10^-34 Js/mol

f is frequency of radiation = 1×10^19 Hz (1×10^19 s^-1)

n = 1×10^44/(6.634×10^-34 × 1×10^19) = 1×10^44/6.634×10^-15 = 1.51×10^58 moles of photons

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

like poles repel so keep pushing north to north and repels funny to see this