Selector help

Selector help

Need help selecting a particular element of this nav bar:
    1. <nav id="nav_bar">
          <ul>
              <li><b><a href="ncs_login.php">NCS Login</a></b></li>"
              <li><a href="net_login.php">Net Login</a></li>"     
              <li><a href="maint_login.php">Maint Login</a></li>
          </ul>
      </nav>

    Tried this to hide the first element : $("#nav_bar[ul][li][b][a]").hide(); and it didn't work.

    If I just use #nav_bar, of course the whole nav bar gets hidden.

    How can I select just that one element?

    Thanks for any help!