Answer:
The answer is A. I took the test today.
Explanation:
Answer:
frequency = 0.47×10⁴ Hz
Explanation:
Given data:
Wavelength of wave = 6.4× 10⁴ m
Frequency of wave = ?
Solution:
Formula:
Speed of wave = wavelength × frequency
Speed of wave = 3 × 10⁸ m/s
Now we will put the values in formula.
3 × 10⁸ m/s = 6.4× 10⁴ m × frequency
frequency = 3 × 10⁸ m/s / 6.4× 10⁴ m
frequency = 0.47×10⁴ /s
s⁻¹ = Hz
frequency = 0.47×10⁴ Hz
Thus the wave with wavelength of 6.4× 10⁴ m have 0.47×10⁴ Hz frequency.
Explanation:
Number of moles(n)=Number of atoms(N)/Avogadro's constant.
Avogadro's constant=6.02×10²³
so we have
n=9.05×10²³/6.02×10²³
n=1.0503moles.
n=mass/molar mass
1.0503=mass/28
mass=1.0503×28
mass=29.4084g