Chem chp 2 Flashcards
What is the definition of matter?
Matter is a substance that has mass and occupies space. All living and non-living things are matter.
What state is dry ice considered to be in?
Solid
What are the three main states of matter?
Solid, liquid and gas
State the particle arrangements for the 3 states of matter
Solid-packed in close and orderly manner
Liquid-closely packed in disorderly manner
Gas- very far apart in disorderly manner
State the attractive forces between particles of the 3 states of matter
Solid- Very strong
Liquid-Less strong
Gas-Very weak
State the kinetic energy of particles of the 3 states of matter
Solid- very low
Liquid- low
Gas- high
What is the particle movement of solids?
Vibrate and rotate about fixed positions
What is the particle movement of liquids?
Slide past one another freely throughout the liquid
What is the particle movement of gases?
Move quickly and randomly in any direction
Define transition temperatures
Transition temperatures are the specific temperatures where heating or cooling of a substance results in ** changes of state** instead of changes in temperatures.
What is temperature?
The measure of the average kinetic energy of particles in a substance.
What happens during changes of state (energy-wise)?
Temperature remains constant as the avg KE of particles does not change.
Thermal energy->CPE and vice versa
Describe melting
KE gained->particles in solid vibrate and move faster when heated
sufficient energy
->overcome forces of attraction holding them in their fixed positions and move around one another randomly.
Describe freezing
Particles in liquid slow down
Thermal energy lost to surroundings when liquid is cooling->KE decreases
Particles eventually settle into fixed positions in an orderly arrangement
Solid is formed
Describe expansion
Solid heated at temps below boiling pt-> cannot spread out freely, strongly attracted
Vibrate more quickly, but with wider spacing