chem- physical properties Flashcards
What is a physical property? (GIVE EXAMPLES)
a property that can be observed with the senses, and can be determined without destroying the object (ex. colour, mass, hardness, melting/boiling point, conductivity)
What is a chemical property? (GIVE EXAMPLES)
is the ability of a substance to chemically react to form new substances, must undergo a chemical change in order to be observed (ex. combustibility, reaction with acid/base)
What is a physical change? (GIVE EXAMPLES)
Name of substance does not change, it’s just in a different form or state, may have new properties, but particles are the same. (ex. ice melting, ripping paper)
What is a chemical change? (GIVE EXAMPLES)
A new substance with new properties is formed. May be difficult or impossible to reverse. Masses may change, total mass does not. (ex. burning wood, metal + HCl)
Name 5 signs of a chemical change
bubbles, precipitate, color change, temperature change, light emitted, volume change, conductivity change, melting/boiling point change, smell or taste change, change in any definining chemical or physical property of a substance
what are 3 properties of solid matter?
definite shape and volume, temperature and pressure have little effect, not easily compressed
what are 3 properties of liquid matter?
definite volume, no definite shape (takes shape of any container), may be compressed slightly, particles can slide past each other easily
what are 3 properties of gas matter?
no definite volume or shape (fills any space), temperature and pressure have large effect, highly compressible
what is plasma? (give examples)
a gaseous mixture of positive ions and electrons (ionized gas), very hot (>1million degrees C), low density, compressible, expand to fill container (ex. stars, lightning)
what is the most abundant state of matter in the universe?
plasma (99%) (even tho its the least abundant on earth)
what is a liquid crystal
a liquid with organized molecules
what is an amorphous material
a substance with an irregular particle arrangement and no definite melting point. (ex. peanut butter, wax, plastic, glass)
what are the 6 molecular properties of gases?
- gas has mass
- gasses are compressible
- gases fill their container
- gases diffuse through each other easily
- gases exert pressure
- pressure of a gas depends on temperature
why do gases have pressure?
particle motion results in collisions with the container
what is an elastic collision (give an example)
no energy lost, ex. gas colliding with container (this allows constant pressure under constant temperature)
do gases have intermolecular forces?
no
what are intermolecular forces?
forces between molecules beside each other, much weaker than a covalent bond
what effects do temperature and IMFs have on viscosity of a liquid?
temp up v down, IMF up v up
what are the 4 types of crystalline solids? (give examples)
covalent network- single element, very strong, ex. diamond, graphite, silicon
ionic solids- ions arrange themselves in an alternating pattern, very stable, ex. NaCl, CaF2
Molecular solids- held together by IMFs, usually soft, ex. I2, S8
Metallic solids- atoms held together by valence electrons, varying strength, ex. copper, silver, lead
are IMFs stronger or weaker than ionic bonds?
weaker
are IMFs between covalent molecules stronger or weaker than those between ionic particles?
weaker
what happens when you boil a liquid in a sealed container
liquid and gas in dynamic equilibrium (no net change, vaporization and condensation happening at the same rate)
What are sublimation and deposition? give examples
s- solid to gas ex. dry ice, air freshner
d- gas to solid ex. frost
explain why sweating works
vapourization is endothermic, the process requires energy, therefore the evaporating sweat molecules take heat from the environment with them.
