A covalent bond is the bond formed by the sharing of a pair of electrons by two atoms.
Your answer is D: A bond between two atoms.
Temperature can change a reaction rate because adding or taking away heat means energy is being added or taken away. When energy is added, the particles speed up, so there is a greater chance of the reactants colliding to form the products, which increases the reaction rate. When energy is taken away, the particles more slower, so they don't collide as easily, which slows down the reaction rate.
Therefore, the answer is D.
1 property
2 procedure
Results
Molar mass of water 18g/mol
Number of mols = 50.0g/18g/mol =2.78 mol
Heat absorbed = 40.7 kj/mol * 2.78 mol = 113.1 kj.