ps ux // Will list all processes with its id(PID)
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1472 0.0 0.2 95464 4752 ? S<sl 09:31 0:00 /usr/bin/pulsea
root 1475 0.6 1.1 59496 23916 ? Sl 09:31 0:09 /usr/bin/compiz
root 1477 0.0 0.9 124628 19316 ? Sl 09:31 0:00 nautilus
root 1483 0.0 0.5 118556 11280 ? Sl 09:31 0:00 nm-applet --sm-
root 1485 0.0 0.3 27408 7240 ? Sl 09:31 0:00 bluetooth-apple
root 1500 0.0 0.1 21704 3308 ? Sl 09:31 0:00 /usr/lib/pulsea
root 1504 0.0 0.4 48420 8352 ? Sl 09:31 0:00 /usr/lib/evolut
root 1537 0.0 0.1 8644 3148 ? S 09:31 0:00 /usr/lib/gvfs/g
root 1541 0.0 0.0 1896 508 ? Ss 09:31 0:00 /bin/sh -c /usr
root 1542 0.0 0.4 28584 9892 ? Sl 09:31 0:00 /usr/bin/gtk-wi
root 1546 0.0 0.1 7796 2816 ? S 09:31 0:00 /usr/lib/gvfs/g
root 1548 0.0 0.1 17996 2248 ? Sl 09:31 0:00 /usr/lib/gvfs/g
root 1551 0.0 0.1 8188 2180 ? S 09:31 0:00 /usr/lib/gvfs/g
root 1554 0.0 0.1 51544 3564 ? Ssl 09:31 0:00 /usr/lib/bonobo
root 1563 0.1 0.6 76696 13716 ? Sl 09:31 0:02 /usr/lib/gnome-
root 1564 0.0 0.5 75424 11224 ? Sl 09:31 0:00 /usr/lib/gnome-
root 1573 0.0 0.4 54444 8520 ? Sl 09:31 0:00 /usr/lib/evolut
root 1579 0.0 0.9 33484 18656 ? S 09:31 0:00 /usr/bin/python
root 1586 0.0 0.6 84924 13324 ? Sl 09:31 0:00 /usr/lib/indica
root 1589 0.0 0.6 85464 12864 ? Sl 09:31 0:00 /usr/lib/indica
root 1591 0.0 0.6 40828 14196 ? Sl 09:31 0:00 /usr/lib/gnome-
root 1592 0.0 0.4 30992 8792 ? Sl 09:31 0:00 /usr/lib/gnome-
kill -9 PID
eg : kill -9 1475