Input (grade 12): The thallium (III) oxide is a black solid which decomposes above 800 Â C, forming the thallium (I) oxide and oxygen.
Output (grade 9): The black oxide, thallium (III) oxide and the hydroxide, thallium (III) hydroxide, are the only stable +3 compounds. They break down to oxygen and thallium (I) oxide when heated.