Question

1. describe at least three different ways that you can identify the formation of a new substance and the evidence you might see. use examples to support your answer.

Explanation:

1. Color change: A chemical reaction often leads to a change in color. For example, when iron rusts, it changes from a shiny metallic color to a reddish - brown color as iron oxide (a new substance) is formed.
2. Gas production: In a chemical reaction, gas can be released. For instance, when vinegar (acetic acid) reacts with baking soda (sodium bicarbonate), carbon dioxide gas is produced, seen as bubbles.
3. Temperature change: An exothermic reaction releases heat and can cause a temperature increase. Burning wood is an example where heat and light are given off as new substances like carbon dioxide and ash are formed. An endothermic reaction absorbs heat, such as when ammonium nitrate dissolves in water, the solution gets colder as a new hydrated ion - solution system is formed.

Answer:

1. Color change, e.g., iron rusting.
2. Gas production, e.g., vinegar and baking - soda reaction.
3. Temperature change, e.g., burning wood (exothermic) or ammonium nitrate dissolving (endothermic).