Answer:
Explanation:
The relationship between angle and wavelength for maxima and minima in Young's double slit experiment is given by
For constructive interference

For Destructive interference

where 

m=order of maxima and minima
for second order maxima i.e. 
For smallest separation taking 



If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
This process shows alpha decay so X represents an alpha particle. The characteristic of alpha decay is that the mass number stays constant while the proton number increases.