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AleksandrR [38]
2 years ago
7

An electron in a hydrogen atom relaxes to the n=4 level, emitting light of 74 THz.

Chemistry
1 answer:
Solnce55 [7]2 years ago
6 0
Delta E = Ef - Ei
E = energy , h = plank constant  , v = frequency
h= 6.626 * 10 ^-34 j*s  ,  T = 10 ^ 12  , v = 74 * 10 ^12 Hz  ,  Hz = s^-1 

E = ( 6.626 * 10^ -34 j*s) ( 74 * 10 ^ 12 s^ -1 )  =   4.90 * 10 ^ -20 J
Delta E  = Ef  -  Ei
-4.90 * 10 ^ -20 J =  -2.18 * 10 ^ -18J ( 1/4 ^2 - 1/x ^2)
0.0225 = 0.0625 -  ( 1/x ^ 2)
0.225 - 0.0625 =  - 1/ x ^ 2 

- 0.0400 = - 1/x ^2    =   -1 / - 0.0400    =   x^2
25   =  x^2 
     x = 5 




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bixtya [17]

Answer:

14.5L

Explanation:

The following data were obtained from the question:

V1 = 14.1L

T1 = 13.9°C = 13.9 + 273 = 286.9K

T2 = 22°C = 22 + 273 = 295K

V2 =?

Using charles' law: V1/T1 = V2 /T2, we can obtain the new volume as follows:

14.1/286.9 = V2 /295

Cross multiply to express in linear form

286.9 x V2 = 14.1 x 295

Divide both side by 286.9

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V2 = 14.5L

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3 years ago
The specific heats of two natural substances are shown in the table. Specific Heat Natural Substance Specific Heat Wet Mud 2.5 J
Novay_Z [31]

The specific heat of a substance is heat released or absorbed by one gram for a change in 1 degree celsius

so higher the specific heat, more the heat required to raise the temperature by same extent or more the heat released on decrease in temperature upto same extent (for two substance)

Here the specific heat of sandy clay is 1.4 J/g °C

So it is less than that of wet mud hence sandy clay is needs to release less energy to decrease its temperature

5 0
2 years ago
When iron pyrite (FeS2) is heated in air, the process known as "roasting" forms sulfur dioxide and iron(III) oxide. When the equ
Ronch [10]

Answer:

The coefficient of O2 is 11

Explanation:

Step 1:

The equation for the reaction:

FeS2 + O2 → SO2 + Fe2O3

Step 2:

Balancing the equation. The equation can be balance as follow:

FeS2 + O2 → SO2 + Fe2O3

There are 2 atoms of Fe on the right side and 1 atom on the left. It can be balance by putting 2 in front of FeS2 as shown below:

2FeS2 + O2 → SO2 + Fe2O3

There are 4 atoms of S on the left side and 1 atom on the right side. It can be balance by putting 4 in front of SO2 as shown below:

2FeS2 + O2 → 4SO2 + Fe2O3

Now, there are a total of 11 atoms of O on the right side and 2 atoms on the left side. It can be balance by putting 11/2 in front of O2 as shown below:

2FeS2 + 11/2O2 → 4SO2 + Fe2O3

Multiply through by 2 to clear the fraction as shown below:

4FeS2 + 11O2 → 8SO2 + 2Fe2O3

Now the equation is balanced.

The coefficient of O2 is 11

8 0
2 years ago
PLZ HELP!!! ILL MARK BRAINLIEST!!! You read an article written by an amateur ghost hunter. It includes the following paragraph.
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4 0
2 years ago
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If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the struct
sashaice [31]

Answer:

(C) bent 109

(2) XY_5Z

Explanation:

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Number of lone pairs = 2

The general formula is - XY_2Z_2

According to VSEPR theory, the atoms will form a geometry in such a way that there is minimum repulsion and maximum stability.  

The central atom has 2 bond pairs and 2 lone pairs. Hybridization is sp³. The geometry is bent shape which has an angle of approximately 105.5°. It original has angle of 109.5° but due to lone pair repulsion, it reduces.

Answer - (C) bent 109

Square pyramidal possibility:- (2) XY_5Z

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