The colors of light emitted from heated atoms had very specific energies.
Speed is different from velocity. Velocity is a vector quantity and has a direction. Speed is a scalar quantity and does not require a direction. The answer must be D).
Answer:
8.61 min
Explanation:
original mass= 12.65
first half life = 12.65/2 = 6.325
second half life = 6.325/2 = 3.1625
Note : 3.1625 is the closest to the value (3.115) given so we work with it
total time for decay =17.22
therefore two decays = 17.22/2= 8.61
Answer:

Explanation:
We can use the equation for the speed

where x is the distance and t the time. In this case we know that the time spent was 2 hours and the distance was 150km. By replacing we have

I hope this useful for you
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