Is it appropriate to have unnecessary Gossip, Chats, with colleagues, friends, during work? If no, How to avoid them?

It is really not appropriate to do that during the work time. It is preferable to clear up to the colleagues and friends that the work time  has to be specialized to accomplish their duties and tasks not to waste the valuable time for chat & gossip.

It is important to reach them and explain that these behaviors and acts are not acceptable during the working time and advise them politely to avoid these things with respect time  of other co-workers.

Gossip or lengthy chats are not recommended

Simple greetings like hi or hello, how are you is fine and is recommended. 

Gossip or discussion  not related to office work is not recommended.

If someone try to gossip, say yes/no for one or two time and then frankly say that you have to finish such task by such and such time. Hope this will work. 

Free will is something important which resembles a asset to employees;nevertheless give them work to talk about and show them minor problems.

That the reasons for negligence and laxity in the enterprise is a frequent chatter staff in matters unrelated to the organization affairs, resulting in a waste of time back injury so it should be placed with deterrent laws mandated employee acting by and accountable if necessary staff monitor Instant professional conscience

No. you can avoid it by implementing internal communication Policy

Unnecessary gossips may create uncertain situations in the workplace in addition to work efficiency.

UNNECESARY GOSSIP  ARE ALLOW OUTSIDE THE WORKPLACE DURING LEISURE HOURS.ONLY A REDUNDANT STAFF WILL HAVE TIME FOR GOSSIP IN THE WORK ENVIRONMENT.

I agree with Mr. Fazlurs answers

Agreed with Fazuir reply --------------------------

Thanks for the invitation. I agree with the given answers from the experts.

Thanks 

Of course it is not appropriate , I agree with Mr. Fazlurs answers