Which statement best identifies a chemical reaction?
Answer and explanation
Correct answer: New substances form, and signs such as a colour change, gas, or a precipitate may be observed
In a chemical reaction, new substances with properties different from those of the reactants are formed. A colour change, evolution of gas, temperature change, or formation of a precipitate may be observed as evidence. In contrast, changing only the position, container, or shape of a substance is generally a physical change and does not produce a new substance.
Frequently asked questions
What is the correct answer to this question?
New substances form, and signs such as a colour change, gas, or a precipitate may be observed
Why is this the correct answer?
In a chemical reaction, new substances with properties different from those of the reactants are formed. A colour change, evolution of gas, temperature change, or formation of a precipitate may be observed as evidence. In contrast, changing only the position, container, or shape of a substance is generally a physical change and does not produce a new substance.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
