Minerals and chemistry thumb|left|200px|Structure of Titan yellow Yellowcake (also known as urania and uranic oxide) is concentrated uranium oxide, obtained through the milling of uranium ore. Yellowcake is used in the preparation of fuel for nuclear reactors and in uranium enrichment, one of the essential steps for creating nuclear weapons. Titan yellow (also known as clayton yellow), chemical formula has been used to determine magnesium in serum and urine, but the method is prone to interference, making the ammonium phosphate method superior when analysing blood cells, food or fecal material. Methyl yellow (p-dimethylaminoazobenzene) is a pH indicator used to determine acidity. It changes from yellow at pH 4.0 to red at pH 2.9. Yellow fireworks are produced by adding sodium compounds to the firework mixture. Sodium has a strong emission at 589.3 nm (D-line), a very slightly orange-tinted yellow. Amongst the elements, sulfur and gold are most obviously yellow. Phosphorus, arsenic and antimony have allotropes which are yellow or whitish-yellow; fluorine and chlorine are pale yellowish gases. Many crystalline chemical compounds, such as 2,4-Dinitrophenol, are yellowish in color.
Minerals and chemistry thumb|left|200px|Structure of Titan yellow Yellowcake (also known as urania and uranic oxide) is concentrated uranium oxide, obtained through the milling of uranium ore. Yellowcake is used in the preparation of fuel for nuclear reactors and in uranium enrichment, one of the essential steps for creating nuclear weapons. Titan yellow (also known as clayton yellow), chemical formula has been used to determine magnesium in serum and urine, but the method is prone to interference, making the ammonium phosphate method superior when analysing blood cells, food or fecal material. Methyl yellow (p-dimethylaminoazobenzene) is a pH indicator used to determine acidity. It changes from yellow at pH 4.0 to red at pH 2.9. Yellow fireworks are produced by adding sodium compounds to the firework mixture. Sodium has a strong emission at 589.3 nm (D-line), a very slightly orange-tinted yellow. Amongst the elements, sulfur and gold are most obviously yellow. Phosphorus, arsenic and antimony have allotropes which are yellow or whitish-yellow; fluorine and chlorine are pale yellowish gases. Many crystalline chemical compounds, such as 2,4-Dinitrophenol, are yellowish in color.