A scientific law<span> is a statement based on repeated experimental observations that describes some aspects of the universe. A </span>scientific law<span> always applies under the same conditions, and implies that there is a causal relationship involving its elements.</span>A scientific theory<span> is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported </span>theories are not "guesses" but reliable accounts of the real world.
Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles =
(1)
Number of zinc atoms is equal to
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,

= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol =
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
Answer:
ΔE(work)= 692 Kj/mole e⁻ = 4.32 x 10²⁴ eV/mole e⁻
Explanation:
ΔE = hc/λ = (6.63 x 10⁻³⁴j·s)(2.99792 x 10⁸m/s)/(1.73 x 10⁻⁷m) = 1.15 x 10⁻¹⁸j/e⁻ x 6.023 x 10²³ e⁻/mole = 691,999 j/mole e⁻ = 692 Kj/mole e⁻ x 6.24 x 10²¹ eV/KJ = 4.32 x 10²⁴ eV/mole e⁻
It is so that you know how far something is from something else, it's a measurement thing.