<u>Given:</u>
Frequency (ν) = 319 THz
<u>To determine:</u>
The wavelength corresponding to the given frequency
<u>Explanation:</u>
Wavelength (λ) and Frequency(ν) are related as:
λ = c/ν
where c = speed of light = 3*10⁸ m/s
Now:
SI unit of frequency is Hertz (Hz) also expressed as cycles per second
i.e 1 Hz = 1 s⁻¹
1 Terahertz (THz) = 10¹² Hz
therefore the given frequency ν = 319 *10¹² s⁻¹
λ = 3 * 10⁸ ms⁻¹/319 *10¹² s⁻¹ = 940 * 10⁻⁹ m
since 1 nanometer (nm) = 10⁻⁹ m
The wavelength is λ = 940 nm
Ans: The infrared wavelength = 940 nm
I'd guess A or D, but my gut says A
Is this a multiple choice question? if it is you can show me the answers and then I can figure it out.
Answer : The Correct answer is Tellurium ( Te)
In the compound Rb₂X , Rb is Rubidium which belongs from s block and group 1. Also its electronic configuration is [Kr] 5s¹ , which suggest that oxidation state of Rb is +1 . Since there are two Rb atoms present so total positive charge is +2 .
The compound is neutral means it has zero total charge so total negative charge is -2 . Also the there is one atom of X , so oxidation state of X must be -2 . Element with -2 oxidation state belong to oxygen family or group 16 . Electronic configuration of oxygen family ends with ns² np⁴ , means if the element accommodate 12 electrons , the configuration will become ns² np⁶ nd⁴ , which in turn says that element should have d orbitals .
Oxygen and sulfur belongs to period 2 and 3 respectively so they cannot have d orbital . Tellurium belongs to period 5 ( same period of Rb), it can extend its configuration to d orbital . So the X element can be "Tellurium " (Te) .