Why cant this script identify my variable?

"destroy" is not the name of the IntValue. destroy is the name of the variable. If you are to search through the part for a "destroy", then you're applying the variable:

local destroy = Instance.new("IntValue", Part)

That doesn't work. what you want to do is simply search it.

 if hit.Name == "Snow" and destroy.Value == 0 then -- this should simply look into the IntValue it created

A much better way of doing this would be to NAME the IntValue, and detect it. Also, there is a more efficient way of running this code

tool = script.Parent
player = game.Players.LocalPlayer
mouse = player:GetMouse()
reload = true
tool.Activated:connect(function()
    if reload == true then
        reload = false
    local Part = Instance.new("Part", workspace)
    Part.Name = "NAMETHIS" -- Name the part as well! Change this to something useful.
    Part.Size = Vector3.new(0.1,0.1,0.1)
    Part.Shape = ("Ball")
    Part.Position = Vector3.new(-3.5,0.5,4.5)
    Part.CFrame = tool.Handle.CFrame
    Part.CFrame = CFrame.new(Part.Position,mouse.Hit.p)
    local v = Instance.new("BodyVelocity", Part)
    v.velocity = Part.CFrame.lookVector *90
    v.maxForce = Vector3.new(math.huge, math.huge, math.huge)
    local destroy = Instance.new("IntValue", Part)
    destroy.Name = "NAME" -- Name it accordingly to how you'll refer to it in other scripts.
    destroy.Value = 0

    Part.Touched:connect(function(hit)
local check = game.Workspace.NAMETHIS.NAME.Value
        if hit.Name == "Snow" and  check == 0 then 
            check.Value = 1
            game.Workspace.NAMETHIS:Destroy()
            local Snow = hit
	    for i= 1,7 do -- this will make the following code run 7 times
		Snow.Transparency = Snow.Transparency + 0.1
                wait(0.1)

            end
            Snow:Destroy()

        end 
    end)
    wait(3)
    reload = true
end
end)