Hydrogen gas
Calcium + Water. In the following demonstration, a chunk of calcium metal is dropped into a beaker of distilled water. After a second or so, the calcium metal begins to bubble vigorously as it reacts with the water, producing hydrogen gas, and a cloudy white precipitate of calcium hydroxide.
The
combustion of heptane (C7H16) in oxygen spontaneously occurs. The products of
the reaction are carbon dioxide and water vapor. The balanced chemical equation
is 7H16 + 11O2 → 7CO2 + 8H2O H
= –2877.5 kJ.
A nucleotide is composed of a phosphate group, sugar, and nitrogen base. DNA is made of 2 strands of nucleotides linked together by covalent bonds between the phosphate and sugar of each nucleotide. The strands of nucleotides are linked together by hydrogen bonds creating DNA. Hope this helps and sorry if I made a mistake.
The statement that best describes the composition of potassium chlorate, KCIO3 is "<span> The proportion by mass of elements combined in potassium chlorate is fixed."</span>
