The relationship between the frequency (f) of an electromagnetic wave, the speed of the wave (which is the speed of light, c) and its wavelength
is given by
Since the wavelength of the radiation in the problem is
, by substituting numbers in the formula we can get the frequency:
The old electricity meters with disk using sapphire bearings for friction to be minimal to not aggravate metering
Answer. 30 minutes
Explanation. If he walks 70 m in one minute how long will it take him to walk 2,100 m. Well, this is a simple division problem (you could also use a ratio box).
2100/70= 30. Hope this helps, let me know if it’s correct so others can use it :)
Good luck.
Hydrogen has one electron in its outermost shell, while fluorine has seven electron in its outermost shell, hence both hydrogen and fluorine needs a single electron to complete its outermost shell.
That's why there is a single bond between hydrogen and fluorine.
Hence both hydrogen and fluorine share one electron with each other, so option "A" is correct.
Answer:
Read below!
Explanation:
You can watch the sun wheel across the sky during the day, and the stars at night. Focus a telescope on any star besides the north star--especially southern stars--and you can watch them drift across your field of view.
An alternative explanation is that all the stars are painted on (or holes in) some canopy that rotates around the earth. This explanation does not account for the motion of the "wanderers," or planets, as the Greeks called them, or for the path of the moon among the stars.
As we know the stars are massive bodies of significant and varying distance to the earth, the notion they all swing around us in unison seems highly implausible
