Converting binding energy of an element to joules

[Hannah1]

Converting binding energy of an element to joules!

The binding energy of Mg-24 is 198MeV. What is this value in Joules? Write your answer correct to three significant figures.


MeV = megaelectron volt
1 megaelectron volt = 1.60217646 × 10-13 joules
198 megaelectron volts = 3.17230939 × 10^-11 joules


198 megaelectron volts = 3.17230939 × 10^-11 joules
So, the answer should be 3.17E-11. Correct?

I got the answer wrong on the homework... Could it be because I didn't add the unit to the end of the answer?
Or am I just completely wrong?

 

[Dick]

The binding energy of Mg-24 is 198MeV. What is this value in Joules? Write your answer correct to three significant figures.


MeV = megaelectron volt
1 megaelectron volt = 1.60217646 × 10-13 joules
198 megaelectron volts = 3.17230939 × 10^-11 joules


198 megaelectron volts = 3.17230939 × 10^-11 joules
So, the answer should be 3.17E-11. Correct?

I got the answer wrong on the homework... Could it be because I didn't add the unit to the end of the answer?
Or am I just completely wrong?

The number is correct. But, yeah, an answer in physics without correct units on it is wrong.

 

[Hannah1]

The number is correct. But, yeah, an answer in physics without correct units on it is wrong.

I added "Joules" to the end of the answer and submitted the homework again, but I still got the answer wrong.

Here are the steps I took to get my answer:

1. I Googled "198 MeV to joules," and Google's built-in calculator gave me "198 megaelectron volts = 3.17230939 × 10^-11 joules" as the result.
2. Next, I simplified the number to three significant figures and got "3.17E-11".
3. Finally, I added Joules to the end of my answer, and submitted "3.17E-11 Joules" as my answer.

Is there another way to solve this problem?
What did I do wrong?

 

[haruspex]

[*]Next, I simplified the number to three significant figures and got "3.17E-11".
[*]Finally, I added Joules to the end of my answer, and submitted "3.17E-11 Joules" as my answer.
[/LIST]

Since it asked for the answer in Joules, it should be expecting just a number. But from another post of yours, it looks like the software is poorly written. Try just "J".

 

[Nickie]

Your answer is correct, but adding the unit at the end would make it more clear and easier to understand. It is important to always include units in your answer, especially in scientific calculations, to avoid confusion and ensure accuracy. So, the complete answer would be 3.17E-11 joules. It is possible that not including the unit may have resulted in points being deducted on your homework. It is always a good practice to double check your work and make sure all units are included.