Key Concepts. 1  The electrons on the outermost energy level of the atom are called valence electrons. 2  The valence electrons are involved in bonding one atom to another. 3  The attraction of each atomâs nucleus for the valence electrons of the other atom pulls the atoms together.
NTSC is the format used in the United States and Canada. NTSC stands for National Television Standard Committee which established the American TV broadcast TV standard as a 525 line broadcast. The NTSC system has higher frame rate (60 Hz) which reduces visible flicker and picture noise.
(1) Short for Phase Alternating Line, the dominant television standard in Europe. The United States uses a different standard, NTSC. Whereas NTSC delivers 525 lines of resolution at 60 half-frames per second, PAL delivers 625 lines at 50 half-frames per second. Many video adapters that enable computer monitors to be used as television screens support both NTSC and PAL signals.