Unit Zero Flashcards
Qualitative property
Information that describes color, odor, shape, or some other physical characteristic (relates to the five senses) (smooth, yellow, round)
Matter
Anything that takes up space and has mass
Particles of matter are always in motion
Kinetic energy (speed) of particles increases as temperature increases
Solid
Motion of particles: tightly packed, not much movement, low KE
Shape: definite
Volume: definite
Liquid
Motion of particles: moderately packed, medium movement/KE, can flow past each other
Shape: indefinite
Volume: definite
Gas
Motion of particles: loosely packed, high movement/KE
Shape: indefinite
Volume: indefinite
Vapor
The gaseous phase of a substance that exists as a solid or liquid at room temperature
Physical property
A quality or condition of a substance that can be observed or measured without changing the substance’s composition (what it’s made up of) (color, solubility, odor, hardness, malleability, density, melting/boiling point)
Solubility
How well a substance dissolves
Chemical property
Can only be observed when substances undergo chemical change
Always results in a change in chemical composition of substances involved (flammability, decomposition, oxidation, explosiveness, corrosion)
Extensive property
Depends on the amount of matter present (volume, mass)
Intensive property
Depends on the identity of the substance, not the amount (boiling point, density, conductivity)
Physical change
Change which alters a given material without changing its composition (cutting/tearing, grinding, changes of state)
Chemical change
Change which alters the chemical composition of a substance (end with a different substance than you started with) (burning, rotting, fermentation, baking)
Signs of a chemical change
- Energy change: energy is often given off or absorbed as heat
- Color change (out of ordinary)
- Odor production
- Production of gas (often seen as bubbles)
- Irreversibility: cannot proceed back to its original form
*often not enough to prove a chemical change, but indicate one
Solid to liquid
Melting
Liquid to gas
Evaporating
Solid to gas
Sublimation
Gas to solid
Depositing
Gas to liquid
Condensation
Liquid to solid
Freezing
Law of conservation of matter
In all chemical and physical changes, matter is neither created nor destroyed
Mass (reactants) = Mass (products)
Do you know how to add and subtract?
Yes
Pure substance
Matter with uniform a and constant composition
Each substance has a unique set of properties (chemical and physical)
Element
Simplest form of matter that can exist under normal conditions
Cannot be broken down into simpler substances, all atoms are the same
Building blocks for all other substances
Compound
Two or more different elements chemically combined to form a new substance
Can be separated into simpler substances only by chemical means, two or more different atoms
Have properties different than the elements they are made from
Mixture
Combination of two or more pure substances
Each substance retains its individual chemical properties
Variable composition
Can be separated by physical means
Heterogeneous mixture
Uneven blend of two or more pure substances
Individual substances remain distinct
Ex: sand and water, chocolate chip cookie
Shake/stir before using
Homogeneous mixture (solution)
Even blend of two or more pure substances Uniform composition Very small particles that don't settle Most clear and not cloudy Ex: Apple juice
Filtration
Uses a porous to separate a solid from a liquid
Distillation
Based on differences in the boiling points of the substances involved
Centrifuge
Rapid spinning that separates the components of a mixture based on their density. Heavy particles will got to the bottom and lighter particles to the top
Decant
Pouring a liquid off of a solid
Chromatography
Based on the ability of each substance to travel or be drawn across a surface
Quantitative Property
Numerical information that tells how much, how little, how big, how tall, or how fast (117 inches, 117 lbs, 117 miles/hour)
