i wanted to know how many keywords can we use on the page because i have heard that google reduces SERP because of keyword spamming. i am goin to publish an article for ubuntu themes i am going to use keywords ubuntu themes download, download ubuntu themes, linux themes, awesome ubuntu themes, awesome linux themes, themes for ubuntu, themes for linux,linux,ubuntu,ubuntu themes is it ok if i use it on the single page ? will it be considered as keyword spamming ?