Define/describe the following terms in your own words:
Physical Change
Chemical Change
Physical change refers to a change in the physical characteristics or properties of a substance without altering its chemical composition. For example, changing the shape, size, or state of matter, such as melting ice into water or breaking a piece of glass, are physical changes. In these changes, the substance remains the same at a molecular level.
Chemical change, on the other hand, involves a transformation at the molecular level where the chemical composition of a substance is altered, forming new substances with different properties. It typically involves the breaking and forming of chemical bonds. Examples of chemical changes include the rusting of iron, the burning of wood or paper, or the digestion of food in our bodies. In these changes, the original substances are converted into new substances.
Physical Change:
A physical change refers to a process in which a substance undergoes a transformation that only affects its physical properties, such as its shape, size, or state of matter (solid, liquid, gas). During a physical change, the identity and chemical composition of the substance remain the same, and no new substances are formed. Examples of physical changes include melting ice, boiling water, crushing a can, or tearing a piece of paper.
To identify a physical change, you can observe the changes in the physical properties of the substance. You can measure the change in size, observe changes in color or state, or test for changes in texture or density. It is important to note that physical changes are typically reversible, meaning the substance can be restored to its original state.
Chemical Change:
A chemical change, also known as a chemical reaction, occurs when one or more substances are converted into new substances with different chemical compositions. During a chemical change, the atoms of the substances rearrange and bond together in new ways, resulting in the formation of new chemical compounds. Examples of chemical changes include burning wood, rusting of iron, digestion of food, or formation of bubbles in a baking soda-vinegar reaction.
To identify a chemical change, several indicators can be observed. One common indicator is the formation of a gas, such as bubbles or fizzing, as well as the release or absorption of energy in the form of heat, light, or sound. Changes in color or odor, as well as the formation of a precipitate (a solid substance formed from a liquid solution), are also signs of a chemical change. It is important to note that chemical changes are generally not easily reversed, and the original substances cannot usually be obtained again through simple methods.