Chapter 3 - States of Matter
Archimedes' Principle
The buoyant force on an object in a fluid is an upward force equal to the weight of the fluid that the object displaces.
melting point
the temperature at which a substance changes from solid to liquid. It depends upon pressure.
condensation point
the temperature at which the gas becomes a liquid.
thermal energy
the total kinetic energy of the particles that make up a substance (atoms); it is dependent upon particle speed and number of particles. (although the particles of steam have more kinetic energy than water, the ocean will have more thermal energy than steam because it contains so many more particles).
buoyant force
the upward force, resulting from the fact that pressure increases with depth, that keeps an object immersed in or floating on a fluid.
sublimation
the process in which a solid changes directly into a gas, such as dry ice.
boiling point
the temperature at which a liquid boils.
freezing point
the temperature at which a liquid changes to a solid.
Pascal's Principle
A change in pressure at any point in an enclosed fluid will be transmitted equally to all parts of the fluid. (if the pressure in a container is increased at any point, the pressure increases at all points by the same amount) (examples: a tube of toothpaste, a hydraulic lift).
True 3
All fluids exert an upward buoyant force on matter.
True 4
An object will float or sink based on its density, not its weight. (example: a ship versus a block of steel).
What causes a change of state?
Energy transfers. For example, a transfer of energy known as heat causes the temperature of a substance to change; if enough energy is added or removed, the substance will change state. Some changes require energy (not just a transfer of energy).
True 5
Fluids move faster through small areas than through larger areas, if the overall flow rate remains constant (example: putting your thumb over a garden hose). Fluids also vary in the rate at which they flow (example: honey versus water).
Solids
Have definite shape and volume.
Liquids
Have variable shape and definite volume.
Gases
Have variable shape and volume.
How does temperature affect movement of atoms and molecules?
The higher the temperature of a substance is, the faster the particles move. At the same temperature, more massive particles will move slower than less massive ones.
True
True or False? Freezing point and melting point occur at the same temperature.
T
True or False? Neither mass nor energy can be created or destroyed.
False
True or False? Temperature changes during changes of state.
viscosity
a liquid's resistance to flow. (honey has a higher viscosity than water).
temperature
a measure of the average kinetic energy of the particles in an object. The faster the particles of matter are moving, the more kinetic energy they have, and the higher the temperature of the object is.
fluids
a non solid state of matter in which the atoms or molecules are free to move past each other; this includes both gas and liquid. (the movement is "fluid"). They exert pressure evenly in all directions.
Bernoulli's Principle
as the speed of a moving fluid increases, the pressure of the moving fluid decreases. (example: a leaf in a pipe that gets narrower).
Change of state
does not change the substance's identity, but does change the energy of a substance.
law of conservation of energy
energy cannot be created or destroyed.
law of conservation of mass
mass cannot be created or destroyed.
kinetic theory
matter is made up of atoms and molecules, which act like tiny particles that are always in motion.
What are the 4 most common states of matter?
solid, liquid, gas, and plasma.
newton
the SI unit of force.
pascal
the SI unit of pressure; equal to the force of 1 N exerted over an area of 1 m2. (symbol, Pa)
energy
the ability to change or move matter, or to do work. For example, electricity, candles, batteries, or food we eat.
pressure
the amount of force exerted on a given area of surface. P=F/A (measured in 1 N/m2). Examples include air pressure, water pressure, blood pressure.
condensation
the change of state from a gas to a liquid. Large numbers of gas particles clump together; energy is released from the gas; the particles slow down.
evaporation
the change of state from a liquid to a gas.
kinetic energy
the energy of motion. (Because all particles of matter are in motion, all matter would have it).
plasma
the most common state of matter, which consists of free-moving ions and electrons, and has variable shape and volume. It is made up of particles that are ionized (electrically charged), and is found in lightning, fire, and the aurora borealis. Similar to gases, but different (for example, they conduct electric currents).
hydraulic devices
use liquids to transmit pressure from one point to another.
constant
without interruption; continual.
