Moles of oxygen = mass/molar mass of O2 = 8/31.998 = 0.25 moles.
Number of particles = moles x 6.02 x 10^23 = 0.25 x 6.02 x 10^23 = 1.505 x 10^23 particles.
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Answer:moles or atom. The SI base unit for amount of substance is the mole. 1 mole is equal to 6.0221415E+23 atom. Note that rounding errors may occur, so always check the results.
Explanation: