AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
An exothermic energy change occurs — heat is released. It can be detected by touching the beaker, which feels hot.
Source: Chapter 1, Section 1.2.1 – Combination Reaction
The examiner looks for two things in one line: (1) the correct term exothermic and (2) the method of detection (touching the beaker/rise in temperature). Both must appear for full credit on a 1-mark question. Avoid writing "endothermic" — the textbook explicitly states "releasing a large amount of heat."