Which of the following is not an indication of a chemical reaction?

Two substances burst into flames on contact.

A substance freezes.

Bubbles form when two substances are combined.

A solid forms when two substances are combined.

Scientists predicted Adamantium would have an Atomic radius of 327 pm. Once the element was measured experimentally, they found that the atomic radius was really 312 pm. Calculate the percent error of their prediction

If the reaction is at dynamic equilibrium at 500 K, which statement applies to the given chemical system? The forward and reverse reactions no longer occur. The rates of the forward and reverse reactions are unequal.

What is the difference between a renewable and nonrenewable resource

A compound is found to contain 6.1% hydrogen and 93.9% oxygen. Find it's empirical formula.

Which statement explains why a C-O bond is more polar than a F-O bond? (1) At STP, carbon has a greater density than fluorine. (2) A carbon atom has more valence electrons than a fluorine atom.

importance of pH value in daily life

How do metallic bonds differ from covalent and ionic bonds

Will ag2so4 precipitate when 100 ml of 5.0*10-2 m agno3 is mixed with 10 ml of 5.0*10-2mna2so4 solution?

How many grams of H₂ are produced with the reaction of 36 grams of water? 2 Na + 2 H20 - > 2 NaOH + h2

Which statement is the best description of a chemical bond? A. A chemical bond connects 2 different molecules. B. A chemical bond holds atoms together. c. A chemical bond turns molecules into atoms. D. A chemical bond identifies atoms in a molecule.