Question

A change in color during a reaction is often a sign that a(n) _____ change has occurred.

1) atomic
2) chemical
3) elemental
4) physical

Answer 1

A change in color during reaction is often a sign that a chemical change has occurred.

Answer 2

A color change during a reaction usually indicates a chemical change, where substances transform into new ones with different properties.

Step-by-step explanation:

A change in color during a reaction is often a sign that a chemical change has occurred. This type of change involves the breaking and forming of bonds between atoms and molecules, leading to the transformation of substances with noticeable changes in properties, such as color, temperature, and the formation of a precipitate or gas.

While a physical change affects only the appearance of a substance without altering its chemical structure, a chemical change results in the production of one or more new substances with different properties. Observations such as color change, temperature change, the emission of light, and the formation of a precipitate provide evidence that a chemical change has taken place.

An example of a chemical change is the rusting of iron, where iron (Fe) reacts with oxygen (O2) to form iron oxide (Fe2O3), a process accompanied by a change in color.