## Search found 8 matches

Sun Apr 15, 2018 10:12 pm
Forum: Photoelectric Effect
Topic: Example 1.5 c
Replies: 3
Views: 95

### Re: Example 1.5 c

In example 1.5 in the textbook part c, we are told to set Ek to 0 to find the longest wavelength or radiation that is able to eject an electron, so hv=phi. They then concluded that lambda=ch/phi. How did they get to this conclusion? Here is the question for everyone else! :) What is the longest wav...
Sun Apr 15, 2018 10:09 pm
Forum: Properties of Electrons
Topic: Photoelectric Effect and its light intensity [ENDORSED]
Replies: 2
Views: 111

### Re: Photoelectric Effect and its light intensity[ENDORSED]

The photoelectric effect works better with shorter wavelengths. Because the energy per photon E=hv depends on the frequency for a higher value, that means that a shorter wave length (c/lambda) gives you a higher frequency, which gives you higher energy that is needed to eject an e-.
Sun Apr 15, 2018 9:50 pm
Forum: Photoelectric Effect
Topic: Example 1.5 c
Replies: 3
Views: 95

### Re: Example 1.5 c

So we know the equation relating wavelength and frequency (lambda,v) to speed of light c. lambda*v=c this can also be rearranged to v=c/lambda dividing each side by lambda. Because h*v=phi, we can substitute v with c/lambda giving us ... (h)(c/lambda)=phi, then you can multiply each side by lambda o...
Sun Apr 15, 2018 9:37 pm
Forum: Properties of Light
Topic: Homework question 1.65
Replies: 2
Views: 133

### Re: Homework question 1.65

You're right the first step is to convert 348 kj*mol^-1 into only J. Once you finish the conversion the J you get is the deltaE because it is the energy needed to break the bond. Now that you have deltaE you can sub it into the equation with the given constants (h,c). Don't forget to convert the ans...
Sat Apr 14, 2018 10:15 pm
Forum: Properties of Light
Topic: Quantized v. Discrete
Replies: 5
Views: 143

### Re: Quantized v. Discrete

Adding on to this! in lecture on 4/11/18 he mentioned "the energy of an electron in the H-atom changes as a function of n"
What is n? Is it a discrete variable? Because the output of the function is energy, what does n represent?
Sat Apr 14, 2018 9:59 pm
Forum: Properties of Light
Topic: Equations [ENDORSED]
Replies: 8
Views: 195

### Re: Equations[ENDORSED]

The c = v x lambda should be used when you know either know the frequency or wavelength. Because c is a constant, the unknown variable (v or lambda) can easily be solved using algebra by isolating the variable. Both equation are used in the e- ejection problems because the v in the energy equation c...
Sat Apr 14, 2018 9:52 pm
Forum: Limiting Reactant Calculations
Topic: Theoretical Yield [ENDORSED]
Replies: 6
Views: 263

### Re: Theoretical Yield[ENDORSED]

1. Find the amount in moles from the given mass. 2. Then with the mole ratio in the chemical equation, convert the amount of the amount in moles from step 1 to amount in moles of the other reactant. 3. Then convert the amount in moles from step 2 to mass. Do you mind explaining the ratio part of ca...
Sat Apr 14, 2018 9:52 pm
Forum: Limiting Reactant Calculations
Topic: Theoretical Yield [ENDORSED]
Replies: 6
Views: 263

### Re: Theoretical Yield[ENDORSED]

1. Find the amount in moles from the given mass. 2. Then with the mole ratio in the chemical equation, convert the amount of the amount in moles from step 1 to amount in moles of the other reactant. 3. Then convert the amount in moles from step 2 to mass. Do you mind explaining the ratio part of ca...