Change particle size?

[This]

I'm trying to achieve the following:
I have a cloud in a scene. When the user touches the cloud, a snow particle is activated. I have it set up: Start Touch>Start Particle. Only issue is that the particle is too long (it juts out over both ends of the cloud). Is there a way to change the length of the particle?

[Aidan_Fire]

At the very top of the particle editor in the first menu of stuff that comes up is a duration slider. EDIT I misread your post, you want to change the x spread, there's a slider further down for that too. X Position Variation.

[This]

@Aidan-Oxley Awesome! Thanks!