What are some major signs of a chemical change?
Some major signs of a chemical change include:
1. Formation of a gas or bubbles
2. Formation of a precipitate (a solid that forms from a chemical reaction in a liquid)
3. Change in color or appearance
4. Evolution or absorption of heat (temperature change)
5. Production of light or flame
6. Release of odor or production of a new smell
7. Irreversibility (the change is permanent and cannot be easily undone)
8. Production of sound or noise
in 4 sentences
1. A chemical change is indicated by the formation of a new substance with different chemical properties than the original substances.
2. It is often accompanied by observable changes such as the release of gas or the formation of a solid precipitate.
3. Chemical changes may also involve changes in energy, such as the evolution or absorption of heat.
4. Overall, the major signs of a chemical change involve the creation of new substances and the occurrence of observable physical changes.
in 4 sentences What are signs that only a physical change has occurred?
1. Signs that only a physical change has occurred include changes in size, shape, or state of matter (such as melting, freezing, or vaporization).
2. Physical changes do not involve the formation of new substances with different chemical properties.
3. The original substances can be easily reversed or separated through physical means, such as by melting or filtering.
4. Unlike chemical changes, physical changes do not typically involve the production of gas, precipitate, or significant energy changes.