Answer:
A. 2.82 eV
B. 439nm
C. 59.5 angstroms
Explanation:
A. To calculate the energy of the photon emitted you use the following formula:
 (1)
     (1)
n1: final state = 5
n2: initial state = 2
Where the energy is electron volts. You replace the values of n1 and n2 in the equation (1):

B. The energy of the emitted photon is given by the following formula:
 (2)
   (2)
h: Planck's constant = 6.62*10^{-34} kgm^2/s
c: speed of light = 3*10^8 m/s
λ: wavelength of the photon
You first convert the energy from eV to J:

Next, you use the equation (2) and solve for λ:

C. The radius of the orbit is given by:
 (3)
   (3)
where ao is the Bohr's radius = 2.380 Angstroms
You use the equation (3) with n=5:

hence, the radius of the atom in its 5-th state is 59.5 anstrongs
 
        
             
        
        
        
The distance covered is  25.9 m.
<h3>How deep is the cave?</h3>
We know that the speed of sound refers to the speed with which an sound moves in an object.
Given that;
speed of sound = 345m/s
Time taken =  0.15s
We know that;
v = 2d/t
v = speed of sound
d = distance
t = time taken
vt = 2d
d = vt/2
d = 345m/s *  0.15s/2
d = 25.9 m
Learn more about speed of sound:brainly.com/question/15137350
#SPJ1
 
        
             
        
        
        
Answer:
Assuming there is no heat loss to the surrounding.
Heat lost by iron equals heat gained by water.
0.2(450)(50-x)=0.2(4200)(x-30)
x=31.94 °C
Explanation:
 
        
                    
             
        
        
        
The question is missing alternatives. Here is the complete question.
An infrared spectrometer on Dawn found something unexpected on Ceres's surface. Its presence suggested that Ceres might have formed farther from the Sun, or been impacted by objects from a more-distant part of the solar system. What was this finding?
1. The fact that Ceres is covered with small dark particles  that appear identical to the composition of Uranus's rings.
2. The presence of a thick cloud layer made of sulfuric acid, similar to what is observed at Venus.
3. The presence of clay-like minerals with ammonia bound up in them.
4. The infrared spectrum of Ceres's surface is essentially identical to that of most objects in the Kuiper Belt.
Answer: 3. The presence of clay-like minerals with ammonia bound up in them.
Explanation: The discovery of ammonia clay-like minerals in Ceres is surprising because it would be encoutered in planets that are far from the Sun, since ammonia requires colder temperatures, which is found beyond Jupiter's orbit, to condense. This finding can ascertain not only the origins of the dwarf planet as how the solar system was formed, were organized and evolved, because understanding where smaller planets are formed is important to determine their destiny.
 
        
             
        
        
        
The moon does not have its own light.