The number of electrons in an element with atomic number 20 is
2 answers:
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Answer:
It took 1.28 seconds to his voice to reach the Earth via radio waves.
Explanation:
The electromagnetic spectrum is the distribution of radiation due to the different frequencies at which it radiates and its different intensities, that radiation is formed by electromagnetic waves, which are transverse waves formed by an electric field and a magnetic field perpendicular to it.
The distribution of the radiation in the electromagnetic spectrum can also be given in wavelengths, but it is more frequent to work with it at frequencies, the highest being that of gamma rays, followed by X-rays, ultraviolet rays and the visible region , and those of lower frequencies, which correspond to infrared, microwave and radio waves.
Light propagates as electromagnetic wave in vacuum with a speed of . Therefore, radio waves will have in vacuum the same speed.
Then, to know the time that it took for its voice, the next equation can be used:
(1)
Where c is the speed of light, d is the distance and t is the time.
Notice that t can be isolated from equation 1.
(2)
Hence, it took 1.28 seconds to his voice to reach the Earth via radio waves.
Answer:
2.63 %.
Explanation:
Given that,
The calculated value of the specific heat of water is 4.29 J/g.C
Original value of specific heat of water is 4.18 J/g.C.
We need to find the student's percent error. The percentage error in any quantity is given by :
So, the student's percent error is 2.63 %.
Answer:
71.19 C
Explanation:
25C = 25 + 273 = 298 K
Applying the ideal gas equation we have
where P, V and T are the pressure, volume and temperature of the gas at 1st and 2nd stage, respectively. We can solve for the temperature and the 2nd stage: