A characteristic of a substance that can be observed
A property that can be observed without changing the identity of the substance
Examples of physical propertys
A property that can only be abserved by changing the substance's composition.
Examples of chemical propreties
Ability to rust
Reactivity with acids or bases
Changes that produce a new kind of matter with different properties are chemical reactions (Rx).
Changes in which the chemical composition of the matter is changed.
After a chemical reaction
Products have different properties than reactants.
NaCl : Salt
Na - explosive metal
Cl2 - Poisonous gas
After aa physical Change
Alter (after the change) a substance without changing it's composition: no new molecules are formed.
ex: grinding, crushing, breaking, changes of state.
Changes of state
Involves either the addition or removal of energy
Rx that takes up heat which speeds up particles
Rx that give up heat thus slowing particles
Changes of state Endothermic
Melting (liquification, fusion)
Solid + heat --> liquid
Liquid + heat --> gass
Changes of state Exothermic
Liquid - heat --> solid
Gas + Heat --> liquid
Skipping the liquid phase step in the changes of state
No liquid state
Solid + heat --> gas
No liquid step
gas - heat --> solid
D = m/V =g/mL = g/cm3
having the structure and form of a crystal
without a clearly defined shape or form
Kinetic Molecular Theory
All matter is compoused of particles in constent motion.
-gas particles move the fastest with elastiic collisions.
The degree or intensity of heat in a substance or object
How does definiton of temperature corresponds to the KMT?
The higher the temperature the faster particels move
The lower the temparature the slower particles move
Kinietic energy in states of matter
Highest kinetic energy is in gas
Lowest kinetic energy is in solid
Connection between KMT and absolute zero?
There is no movement of particles at absloute zero (-273oC)
The lowest theoreticly possible temperature at which motion of particles that consititutes heat would be minimal.
Why is the Kelven temperature scale refferd to as the absolute temperature scale?
No negitive temperatures, absolute value.
A form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection, and through empty space by radiation.
difference between heat and temperature?
Temperature is a number. That number is related to energy, but it is not energy itself.
-number that is related to the average kinetic energy of the molecules of a substance.