How can you publish a scientific article in a national or international journal?

Anyone can submit an article for publication. Write it up and mail it to the editors of any journal where you wish to get published. Sounds simple, and it is. But there's a catch. Though "anyone" can submit an article to any journal for publication, the journals are very "picky" about what they print. If you were the editor of a top-flight scientific publication, would you accept an article from a high schooler? Probably not, at least not when a flock of PhD's are filling your in box with killer stuff. Make sense? Do not let anything deter you if you wish to write for publication. Prepare your best work and submit it. Edit it and resubmit it if you have to. Shop it around. Whatever it takes. Good luck.