Answer:
400 or 4x102 indicates only onesignificant figure. (To indicate that the trailing zeros are significant a decimal point must be added. 400. has threesignificant digits and is written as 4.00x102 in scientific notation.) Exact numbers have an infinite number of significant digits but they are generally not reported.
Best Answer: 4.52 X 10²³ atoms. Use Avogadro's number to multiply 0.750 moles times 6.022 X 10²³
The frequency and energy of most energetic of these photons is
Hz and
J respectively.
The high energy photons will have least wavelength. Taking the given less wavelength for calculation of frequency and energy of photons.
λ = 2200 Å
Also, we know, 1 Å =
m
So, λ = 
λ =
<em> </em>m
Now, calculating frequency using the formula -
c = fλ, where c is speed of light, f is frequency and λ is wavelength.
We know, c =
m/s
f = c/λ
f = 
frequency =
Hz
Now, calculating Energy through the formula -
E = hf, where E is energy, h is planck's constant and f is frequency
Value of planck's constant =
Js
E =
*
Energy =
J
Thus, frequency and energy of photons is
Hz and
J respectively.
Learn more about energy of photon -
brainly.com/question/15946945
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Answer:
Elements -------> Formulae
a). Tungsten ----> W
b). Lead -----------> Pb
c). Calcium ------> Ca
d). Ziriconium --> Zr
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