The correct answer is 740
The Neutron-to-Proton Ratio. Hope this helps Sorry if it's wrong I'm a little rusty on Physics.
Answer:
If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close. Keep in mind that you should be in a safe place while counting.
Explanation:
