Oxide copper, so it displaces copper (II) oxide to form zinc oxide: Apart from metals, hydrogen can also displace metal oxides to form hydrogen oxide, also known as water: Since metals that are reactive form oxides that are stable, some metal oxides must be electrolyzed to be reduced. This includes sodium oxide, potassium oxide, calcium oxide, magnesium oxide, and aluminium oxide. The oxides must be molten before immersing graphite electrodes in them: Oxides typically react with acids or bases, sometimes both. Those reacting only with acids are labeled basic oxides. Those reacting only by bases are called "acidic oxides". Oxides that
Chromium(IV) oxide of both the chromium dioxide pigment and chrome tapes, basing its VHS & S-VHS video tape, audio cassettes, and 3480 data cartridges on this formulation. Dupont and BASF had also introduced chrome-cobalt "blended" oxide pigments which combined about 70% cobalt-modified iron oxide with 30% chrome oxide into a single coating, presumably to offer improved performance at lower costs than pure chrome. Many high grade VHS tapes also used much smaller amounts of chrome in their formulations because its magnetic properties combined with its cleaning effects on heads made it a better choice than aluminium oxide or other non-magnetic materials added