A physical property is what a substance is like; it's directly observable. On the other hand, a chemical property is how a substance behaves; its reactivity.
Examples of a physical property are: color, texture, boiling point, freezing point, and melting point.
Examples of a chemical property are: flammability, combustion, and formation of a precipitate.
Answer: a. The concentrations of the reactants and products have reached constant values
Explanation:
The reactions which do not go on completion and in which the reactant forms product and the products goes back to the reactants simultaneously are known as equilibrium reactions. For a chemical equilibrium reaction, equilibrium state is achieved when the rate of forward reaction becomes equal to rate of the backward reaction.
Equilibrium state is the state when reactants and products are present but the concentrations does not change with time and are constant.
Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as 
K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.
For a equilibrium reaction,
![K_{eq}=\frac{[B]}{[A]}](https://tex.z-dn.net/?f=K_%7Beq%7D%3D%5Cfrac%7B%5BB%5D%7D%7B%5BA%5D%7D)
Thus the correct answer is the concentrations of the reactants and products have reached constant values.
A bicycle rusting after it is left in the rain is an example of a chemical reaction because it involves oxidation (Option d).
<h3>What is a chemical reaction?</h3>
A chemical reaction can be defined as a phenomenon in which one or more substances called reactants react to form one or more different compounds, which are known as products.
A chemical reaction may include an enzyme that works to increase the seed of the reaction in normal conditions by lowering the activation energy of the reaction.
Therefore, we can conclude that a chemical reaction such as oxidation in a bicycle is a process where reactants combine or break down to form the products of such reaction.
Complete question:
Which of the following situations contains an example of a chemical reaction?
a. Ice forming after water is placed in a freezer
b. Watercolor paint drying on paper
c. a sugar cube dissolving in a glass of water
d. a bicycle rusting after it is left in the rain
Learn more about chemical reactions here:
brainly.com/question/11231920
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C. Accelerating should be the correct onw
