Chapter 12 Properties of Matter
how can the strength of an object be determined?
-how much the object bends under applied force -how much the object can withstand before breaking
what two things does the density of a solid depend on?
-the individual mass of each atom or molecule -how closely the atoms or molecules are packed together
what is a Pascal?
A unit of pressure equal to a force of 1 Newton acting over 1 square meter
what is it called when any change transforms one substance into a different substance?
a chemical change
what is mass?
a fundamental property of matter
what is viscosity?
a measure of a fluid's resistance to flow
what is hardness?
a measure of a solid's resistance to scratching
what is tensile strength?
a measure of how much stress from pulling, or tension, a material can withstand before breaking
what is amorphous?
a random arrangement of atoms or molecules in a solid
what is Bernoulli's principle?
a relationship that describes energy conservation in a fluid
do all solid material expand as the temperature increases?
almost all solids
what is highly malleable metal?
aluminum
if you know an object's weight how can you automatically know if it sinks or float?
an object sinks if the density is greater than the liquid it is submerged in and an object floats if its density is less that the liquid
what is crystalline?
an orderly, repeating arrangement of atoms or molecules in a solid
what is a fluid?
any matter that flows when force is applied
when does the density of solids decrease?
as the temperature increases because solids expand when heated
if one variable increases along a streamline what happens to the other 2 variables?
at least one must decrease
why are amorphous solid softer?
because the molecules are not tightly connected to its neighboring molecules
why do gases have a low density?
because the molecules in a gas are far away for each other
what are chemical properties?
characteristics that can only be observed when one substance changes into a different substance
what are physical properties?
characteristics that you can observe directly
What causes pressure?
collisions frome atoms and molecules
what do physical properties included?
color, texture, density, brittleness, and state of matter
are most solids on earth crystalline or amorphous?
crystalline
what is the formula for density?
density = mass/volume
what is the hardest natural substance on Earth?
diamond
what are high-viscosity fluids?
fluids that take longer to pour fro their containers
what is weight?
force caused by gravity
what is the formula for force?
force= pressure x area
what is a good example of a brittle material?
glass
what material barely expands?
glass
what are the 3 variables that are related by energy conservation?
height, pressure, and speed
what are streamlines?
imaginary lines drawn to show the flow of fluid
how does pressure act?
in all directions EXCEPT the direction of the applied force
what is a physical change?
is any change in the size, shape, or phase of matter in which the substance does not change
what is an example of a high viscosity fluid?
ketchup
are mass and weight the same thing?
no
do size and shape change a material's density?
no
does an incompressible fluid decrease in volume when pressure is increased?
no
are chemical changes reversible?
no, not easily
what material expands a great deal?
plastic
what is one of the densest metals?
platinum
what does differences in pressure create?
potential energy in fluids
what is psi?
pounds per square inch
what is the formula for pressure?
pressure = force/area
in addition to potential and kinetic energy what else do fluids have?
pressure energy
the strength of the buoyant force is ___________ to the volume of the part of the object that is submerged.
proportional
what are examples of amorphous solids?
rubber, plastic, wax, and glass
what are examples of crystalline materials?
salts, minerals, and metals
amorphous solids are often ________ and more _______ than crystalline solids
softer, elastic
what phase are material most dense in?
solid
what is Archimedes' principle?
states that the buoyant force on an object is equal to the weight of the fluid it displaces
what material has a high tensile strength?
steel
what is it call if friction is neglected, the total energy stays constant?
Bernoulli's principle
what is malleability?
the ability of a solid to be pounded into thin sheets
what is elasticity?
the ability to be stretched or compressed and the return to original size
what is ductility?
the ability to bend without breaking
what ability does elasticity give objects?
the ability to bounce and withstand impact without breaking
what is strength?
the ability to maintain shape under the application of force
what is pressure?
the amount of force exerted per unit of area
why do objects float?
the buoyant force is greater than the object's weight
why do objects sink?
the buoyant force is less than the object's weight
what is buoyancy?
the measure of the upward force that a fluid exerts on an object that is submerged
what is Pascal's Principle?
the pressure applied to an incompressible fluid in a closed container is transmitted equally in all parts of the fluid
how is viscosity determined?
the shape and size of the particles
what is thermal expansion?
the tendency of the atoms or molecules in a substance (solid, liquid, or gas) to take up more space as the temperature increases
what is brittleness?
the tendency to crack or break (the opposite of elasticity)
what is average density?
the total mass divided by the total volume
when temperature increases what happens to atoms and molecules?
the vibration of atoms and molecules increase too
what happens when the temperature of a liquid increases?
the viscosity decreases
what does the strength of buoyant force depend?
the volume of the object the is submerged
what allows metals to be formed into wires?
their ductility
what do chemical and physical properties help us with?
they help us distinguish substances from one another and help us choose which substance to use for specific purposes
what is an example of a low viscosity fluid?
water
what material have a low tensile strength?
wax, rubber, and brittle materials
why is ice less dense than liquid water?
when water molecules freeze into ice crystals they form a pattern that has a large amount of empty space
what is the density of water?
1.0 g/cm3
what is platinum's density?
21.5 g/cm3
