4. Given the data shown, what two substances does the unknown mixture contain? Substance Appearance
Vinegar
Litmus
(ph)
R-B Base
B-R Acid
Biuret
(protein)
lodine
(starch)
Powder
0
+
Baking
Powder
Baking
Soda
Corn
Starch
Powder
Base
+
Powder
0
Gelatin
Crystal
Acid
+
Salt
Crystal
0
Unknown
Acid
Crystal
& Powder
Mixed
Mixed
A. Gelatin and baking powder
B. Gelatin and baking soda
C. Gelatin and corn starch
D. Salt and corn starch

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.