Answer:
1.5×10⁷ Hz
Explanation:
From the question given above, the following data were obtained:
Wavelength of radio wave (λ) = 20 m
Frequency (f) =?
Frequency and wavelength of a wave are related by the following equation:
v = λf
Where:
'v' is the velocity of electromagnetic wave.
'λ' is the wavelength
'f' is the frequency.
With the above formula, we can obtain the frequency of the radio wave as illustrated below:
Wavelength of radio wave (λ) = 20 m
Velocity (v) = 3×10⁸ m/s
Frequency (f) =?
v = λf
3×10⁸ = 20 × f
Divide both side by 20
f = 3×10⁸ / 20
f = 1.5×10⁷ Hz
Thus the frequency of the radio wave is 1.5×10⁷ Hz
Use the volume and density of the gold statue to calculate the mass of the statue.
density = mass / volume, or rearranged, mass = density • volume
Convert the volume of the statue from L to mL so volume unit agrees with density unit
mass of statue = 19.3 g/mL • 1000 mL = 19 300 g
Mass of sand must be same as the mass of the statue, 19 300 g
Use the mass and density of the sand to calculate the volume of sand needed
density = mass / volume, or rearranged, volume = mass / density
volume of sand needed = 19 300 g / 23 g/mL = 8391 mL or 8.391 L
1b
Calculate the density of the statue from the measured mass and volume. If the calculated density agrees with the known density of gold, then the statue is made from pure gold.
density = mass / volume
Convert the mass from kg to g as you want the answer in g/mL so you can compare it to the reference value of gold given in the problem. 16.5 kg • 1000 g / 1 kg = 16 500 g
density of the statue = 16 500 g / 954 mL = 17.3 g/mL
Since this density, 17.3 g/mL is significantly different from the known density of gold, 19.3 g/mL, the statue cannot be made of pure gold. The gold was mixed with a less dense metal.
Greater the Ka value greater is the acid strength. Among these three acids HClO3 is the strongest acid, with greatest Ka and lowest pKa value (-1), Then comes HBrO3, its the second most strongest acid among the three, its Pka value is 0.7, higher than HClO3 but smaller than HIO3 (i.e. 0.77) which the weakest acid among the three.
This is a characteristic of a Thermosetting polymer.
