Examples of Physical Changes

Adding or removing energy from matter causes a physical change as matter moves from one state to another. Physical changes can also be caused by motion and pressure. Melting and freezing. When heat is applied to a solid, its particles begin to vibrate faster and move farther apart.

Atoms overcome the attractive forces between them through vaporization and sublimation. In vaporization, the atoms are from gas to liquid while in sublimation, it is from solid to gas which skips liquid state.

• Crushing a can.
• Melting an ice cube.
• Boiling water.
• Mixing sand and water.
• Breaking a glass.
• Dissolving sugar and water.
• Shredding paper.
• Chopping wood.

Answer: What happens if atoms lose energy during a change of state? The atoms are pushed apart by repulsive forces and become less organized. The atoms are pulled together by attractive forces and become less organized.

Atoms lose energy as a gas changes to a solid. Atoms gain energy during evaporation and boiling.

MELTING When ice melts, its temperature remains constant until all the ice turns to water. Continued heating of liquid water causes the molecules to vibrate even faster, steadily raising the temperature. FREEZING When liquid water freezes, it releases thermal energy and turns into the solid state, ice.

Melting is a process that causes a substance to change from a solid to a liquid. Melting occurs when the molecules of a solid speed up enough that the motion overcomes the attractions so that the molecules can move past each other as a liquid.

When a solid is heated the particles gain energy and start to vibrate faster and faster. At this point the solid is melting to form a liquid. The particles in the liquid are the same as in the solid but they have more energy.

solids

The change from solid to liquid is called melting or fusion. When a liquid is steadily heated, the particles move rapidly until many of them have sufficient energy to escape from the liquid and form a gas. This change of state is called evaporation. The liquid can also be changed to the solid state.

A change of state occurs whenever matter changes from one state to another. Common states of matter on Earth are solid, liquid, and gas. Changes of state are physical changes in matter. They are reversible changes that do not change matter’s chemical makeup or chemical properties.

Physical changes alter only the size, shape, form or matter state of a material. Water boiling, melting ice, tearing paper, freezing water and crushing a can are all examples of physical changes. On the other hand, chemical changes are a bit different. In a chemical change, a new substance is formed.

Examples of reversible changes

• Melting: Melting is when solid converts into a liquid after heating. Example of melting is turning of ice into water.
• Freezing: Freezing is when a liquid converts into a solid. Example of freezing is turning of water into ice.
• Boiling: Boiling is when a liquid converts into a gas.

Dissolving a solid in liquid, such as table salt in water, is a physical change because only the state of the matter has changed. Physical changes can often be reversed. Allowing the water to evaporate will return the salt to a solid state.

A chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products. Chemical reactions differ from physical changes, which include changes of state, such as ice melting to water and water evaporating to vapor.

The average kinetic energy of the solute molecules also increases with temperature, and it destabilizes the solid state. The increased vibration (kinetic energy) of the solute molecules causes them to be less able to hold together, and thus they dissolve more readily.