Question

Which process is a chemical change?

1) burning a match
2) boiling water
3) melting ice
4) breaking glass

Answer 1

Burning a match is a chemical change as it results in new substances being created from the original material.

Step-by-step explanation:

The process that is a chemical change among the given options is burning a match. In Chemistry, a chemical change is defined as a process where the substance's molecular composition is altered, resulting in new substances with different properties. Burning a match involves the substance in the match igniting and undergoing combustion, changing the chemicals in the match into different substances like carbon dioxide, water, and ash.

For example, when a fire rages in a fireplace, it is similar in nature to a match burning as it represents a chemical change, transforming wood into different substances such as carbon dioxide and ashes. Similarly, transforming bread dough into fresh bread in an oven is a chemical change because the heat causes chemical reactions in the dough, leading to new substances like baked bread.

Answer 2

Burning a match is a chemical change as it involves the combustion of the matchstick, resulting in the formation of new substances such as ash, smoke, and gases. The answer is 1) Burning a match.

Step-by-step explanation:

A chemical change involves the formation of new substances with distinct properties, while a physical change only alters the state or appearance of a substance without forming new ones. Let's analyze each option:

1) Burning a match: This is a chemical change because it involves the combustion of the matchstick, leading to the formation of new substances such as ash, smoke, and gases.

2) Boiling water: This is a physical change as it involves a state change from liquid to gas without altering the chemical composition of water molecules.

3) Melting ice: This is also a physical change, as it involves a phase transition from solid to liquid without changing the chemical composition of water.

4) Breaking glass: Breaking glass is a physical change because it only changes the physical state of the glass without altering its chemical composition.

In summary, option 1, burning a match, is the process that represents a chemical change.