Notes on Chapters 2-3: Matter

Matter – anything that has MASS and takes up space (VOLUME)

Particle Theory of Matter
o Tiny particles (atoms and molecules) that make up matter and are in constant motion
o The state of matter depends on the amount of kinetic energy (motion) of the particles

Physical Properties
o Can be observed or measured without changing the identity of the matter
o Examples: color, mass, volume, size, shape, odor, texture, density, conductivity, malleability,
ductility, solubility
Conductivity: ability to transfer thermal energy from Malleability: ability to be pounded into thin
one area to another (metal spoon in hot liquid)
sheets (aluminum foil)
Ductility: ability to be drawn or pulled into a wire
Solubility: ability to dissolve into another
(wires)
substance (sugar into water)

Chemical Properties
o Describe a substance based on its ability to change into a new substance with different properties
o Examples: flammability, combustibility, Reactivity (with water, oxygen, acids, bases)
Flammability: ability to burn and Combustibility: ability to burn
Reactivity: when two substances
easy to ignite (spark into
and difficult to ignite (paper and
get together, something happens
gasoline)
wood burning)
(rust from metal, water, and air)

Physical Changes
o Change that affects one or more physical properties of a substance
o Examples: paper ripping, cutting hair, melting butter, breaking a pencil, freeze water into ice cubes

Chemical Changes
o Occurs when one or more substances are changed into entirely new substances with different
properties
o Examples: smoke, color change from chemicals, bubbles, new smell (sour milk)

Physical vs. Chemical Changes
Physical Changes
o Can be reversed
o Still looks like the original substance
o Change in the state of matter
Chemical Changes
o Cannot be reversed
o Looks different than the original substance
o Completely new substance(s) formed
Four States of Matter: Solid, Liquid, Gas, Plasma

Solids
o Particles are held close together by strong atomic forces between the particles
o Not enough kinetic energy for particles to change position
o Definite shape and volume
o Does not take the shape of its container

Liquids
o Particles are very close together
o Have enough kinetic energy to flow over and around each other but not enough to separate completely
o Liquids are able to spread out and flow
o No definite shape, but a definite volume
o Takes the shape of its container

Gases
o Particles have more kinetic energy than liquids and can separate completely from one another
o Gas particles spread apart to evenly fill a container
o No definite shape or volume
o Takes the shape of the container and can be compressed into a smaller volume

Plasma
o Gas-like mixture of positively and negatively charged particles
o At high temperatures, particles collide so violently they break into smaller charged parts.
o Most common form of matter
o Examples: sun, stars, fire, lightning, northern lights, nuclear explosions