Achemist identifies compounds by identifying bright lines in their spectra. she does so by heating the compounds until they glow, sending the light through a diffraction grating, and measuring the positions of first-order spectral lines on a detector 15.0 cm behind the grating. unfortunately, she has lost the card that gives the specifications of the grating. fortunately, she has a known compound that she can use to calibrate the grating. she heats the known compound, which emits light at a wavelength of 461 nm, and observes a spectral line 9.95 cm from the center of the diffraction pattern. part a: what is the wavelength emitted by compound a that have spectral line detected at position 8.55 cm? part b: what is the wavelength emitted by compound b that have spectral line detected at position and 12.15 cm?

PART A: 412.98 nm

PART B: 524.92 nm

Explanation:

The equation below can be used for a diffraction grating of nth order image:

n*λ = d*sinθ

Therefore, for first order images, n = 1 and:

λ = d*sinθ.

The angle θ can be calculated as follow:

tan θ  = 9.95 cm/15.0 cm = 0.663 and

θ = (0.663) = 33.56°

Thus: d =λ/sin θ  = 461/sin 33.56° = 833.97 nm

PART A:

For a position of 8.55 cm:  

tan θ  = 8.55 cm/15.0 cm = 0.57 and

θ = (0.57) = 29.68°

Therefore:

λ =d*sin θ  = 833.97*sin 29.68° = 412.98 nm

PART B:

For a position of 12.15 cm:  

tan θ  = 12.15 cm/15.0 cm = 0.81 and

θ = (0.81) = 39.01°

Therefore:

λ =d*sin θ  = 833.97*sin 39.01° = 524.92 nm

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.