Question | Answer |
The three states of matter commonly found on Earth are ___, liquid, and solid. | gas |
Stars and lightning are examples of _______ (hint: a fourth state of matter), which exists as a gas (hint: a state of matter) that has an electrical charge. | plasma |
The motion of particles is called ____ motion, because particles move in any direction and can have different speeds. Colliding particles can change speed and direction. | random |
Moving particles are attracted to each other due to their ______ force. | attractive |
As particles move closer to each other, their attractive force ____; as particles move farther apart, their attractive force decreases. | increases |
A ____ is matter that has a fixed shape and a fixed volume. | solid |
Strong attractive forces in a solid keep ____ close together. | particles |
Because each particle moves only a short distance back and forth between neighboring particles, the shape and ____ of the solid remain fixed. | volume |
Liquid is matter with a fixed volume but not a fixed ___. | shape |
The particles in a liquid are farther apart, and their attractive ___ is less than in a solid. | force |
Particles in a liquid move ___ freely than particles in a solid. | more |
A ___ is matter with no fixed volume and no fixed shape. | gas |
The particles in a gas are far apart and have little ___ force. | attractive |
Particles in a gas move freely to fill whatever ___ they are in. | container |
Particles in motion have ___ ___; moving objects such as a ball have kinetic energy, too. | kinetic energy |
_____ is a measure of the average kinetic energy of all particles in an object. | Temperature |
Warmer objects have a ___ average kinetic energy and therefore have a higher temperature than cooler objects. | higher |
A ___ is used to measure temperature. | thermometer |
Particles in the thermometer’s gauge increase their ___ when heated and start moving farther apart, causing the liquid in the thermometer to rise. | speed |
The total energy of the particles of a substance is its ___ energy. | thermal |
Thermal energy includes the kinetic energy and ___ energy of a substance’s particles. | potential |
A substance’s liquid state has more thermal energy than its ___ state. | solid |
A substance’s ___ state has more thermal energy than its liquid or solid state. | gas |
Thermal energy can be ___ to or removed from a substance. | added |
When the kinetic energy of a material’s particles increases, the ___ of the material increases. | temperature |
When the potential energy of a material changes, the material’s ___ of matter changes. | state |
The ___ ___ of a material is the temperature at which it changes from a solid to a liquid. | melting point |
The ___ ___ of a material is the temperature at which material changes from a liquid to a solid. | freezing point |
Freezing and melting are ___ processes. Freezing involves removing thermal energy from a substance, while melting involves adding thermal energy. | opposite |
The change from a liquid to a gas state is called ____. | vaporization |
Vaporization that occurs within a liquid is called ___. | boiling |
The ___ ___ is the temperature at which a liquid changes to a gas. | boiling point |
Vaporization at the surface of a liquid is ___. | evaporation |
Evaporation can occur at temperatures below the ____ point. | boiling |
The boiling point of a liquid depends on the ___ exerted on the liquid. The higher the pressure on the liquid, the higher the boiling point is. | pressure |
The state change of a material from a gas to a liquid is called ___. | condensation |
___ and condensation are opposite processes, though they occur at the same temperature. | Vaporization |
When ice is changed to liquid water, the temperature of the ice rises to the ____ point of ice. At the melting point, the temperature remains the same as thermal energy is added until all the ice becomes liquid. | melting |
When liquid water is heated, its temperature increases until it reaches its ____ point. There, the water temperature remains the same until all of the liquid water changes state to become water vapor. | boiling |
Changes in state can be ____. | reversed |
___ is the change of a solid to a gas without going through the liquid state. | Sublimation |
___ is the change in state of a gas to a solid without going through the liquid state. | Deposition |
For a material to change from one state of matter to another, ___ ___ must be added to or removed from the material. | thermal energy |