Answer:
C
Explanation:
For electromagnetic waves frequency X wavelength = speed of light
f * 2.2 x 10^-11 = 3 x 10^8 m/s
f = 3 x 10^8 / 2.2 x 10^-11
= 1.36 x 10 ^19
= 1.4 x 10^19 with two significant digits
<u>Answer:</u> The mass of sodium chloride solution present is 0.256 grams.
<u>Explanation:</u>
We are given:
39.0 % of sodium in sodium chloride solution
This means that 39.0 grams of sodium is present in 100 grams of sodium chloride solution
Mass of sodium given = 100 mg = 0.1 g (Conversion factor: 1 g = 1000 mg)
Applying unitary method:
If 39 grams of sodium metal is present in 100 grams of sodium chloride solution
So, if 0.1 grams of sodium metal will be present in =
of sodium chloride solution.
Hence, the mass of sodium chloride solution present is 0.256 grams.