I think the answer is choice D
Answer:
They both go backward because of force.
Explanation:
The logic behind this answer is that child right and pushes away causing her to go backward meaning her partner is being pushed backwards to.
(Hope this was helpful!)
Water, <span>rusts a nail faster</span>
Emission spectrum results from the movement of an electron from a higher to a lower energy level. The frequency of the photon is 5.5 * 10^14 Hz.
From the formula;
E = hc/λ
h = Plank's constant =
Js
c = speed of light= 
λ = wavelength = 
m
E = 
E =
J
Also;
E =hf
Where;
h = Planks's constant
f = frequency of photon
f = E/h
f = 
f = 
Hz
Learn more: brainly.com/question/18415575
Let us assume that there is a 100g sample of Opal. The masses of each element will be:
29.2g Si
33.3g O
37.5g H2O
Now we divide each constituent's mass by its Mr to get the moles present
Si: (29.2 / 28) = 1.04
O: (33.3 / 16) = 2.08
H2O: (37.5 / 18) = 2.08
Now we divide by the smallest number and obtain:
Si: 1
O: 2
H2O: 2
Thus, the empirical formula of Opal is:
SiO2 . 2H2O
