Chemistry 1-3 Flashcards
Matter
-any substance that takes up space & has mass/weight
mass = total # of particles
weight = gravitational pull
1. all matter is made of tiny particles
2. particles attract each other
3. particles are always in motion
4. there are spaces between particles
4. all pure substance are made up of its own kind of particle
Pure Substances
-Substance/substances not physically mixed
Element- can’t be broken down (1 capital letter on periodic table)
Compound- 2+ elements combined with chemical reaction
Homogenous Solution
-Appears as 1 substance
-Different particles attracted & evenly distributed
-Can be separated physically (boiling)
-Solvent wraps around solute particles
solute = is dissolves
solvent = does dissolving
Heterogenous Mixture
-2+ parts seen
Colloid- small particles don’t settle, cloudy, scatters light (milk, jello, fog)
Suspension- particles settle after mixing, different parts called phases (dressing, sandy water)
Mechanical Mixture- unsuspended 2+ parts seen, separated mechanically/filtering (soil, trail mix, cc cookies)
Emulsions-substances needing emulsifying agent to stay together (mayo)
Physical Change & Properties
-Nothing new created (reordering of parts/state changes)
-Physical characteristics describing matter, observed/measured without altering material
ex: color, viscosity, boiling, conductivity, solubility
Chemical Change & Properties
-Particles combine making something different
-Characteristics describing matter, observed by attempting to alter material
ex: reactions w other substances (acid, H2O, O2), baking, temp changes, new properties, light creation, gas bubbles
Quantitative & Qualitative
Quantitative = property measured with #’s number (temps, solubility, boiling point)
Qualitative = property observations (color, texture, clarity)
-Can be both
Theories of Matter
Theory = explanation of observable phenomenon supported by research & evidence
Law = supported explanation of what happens without knowing why (gravity)
Atomic Structure
Atom- smallest piece of matter with elements properties (can have same element with different # of neutrons)
Protons- positively charged (#’s determine what element it is)
Electrons- negatively charged, constantly moving around nucleus
Neutrons- no charge
Nucleus = contains protons, neutrons, & holds all atom’s mass
Electron Cloud = surrounds nucleus
Atom Theories
- Billiard Ball / Dalton’s = atoms are invisible, solid, & unbreakable
- Plum Pudding / Thomson’s = both positive & negative charges present through atom
- Cherry Pit / Rutherford’s = middle has nucleus & rest is mostly empty with few electrons
- Solar System / Bohr’s = electrons move in defined path/ orbit around protons & neutrons
- Electron Cloud = electrons move around nucleus in cloud
Solubility & Concentration
Solubility- mass of solute able to dissolve in specific solute (undersaturated, saturated, super saturated)
Concentration- mass of solute dissolved per ml of solvent
Atom Evolution
Cathode Ray Tube- used by Thomson to determine atoms were composed of charged & negatively charged parts
Gold Foil Experiment- Rutherford fired alpha particles at thin gold sheet, most particles would go through & few were deflected, theorized very dense positively charged mass centre (nucleus) with electrons orbiting it
Spectroscopy- used by Bohr, produces distinct emission lines from elements
Precipitate
-Insoluble solid formed in chemical reaction
Laws
Law of Conservation of Mass- in chemical change total mass of new substance = total mass of OG substance (mass doesn’t disappear)
Law of Definite Properties- compounds are pure substances containing 2+ elements combined in fixed proportions
Law of Multiple Proportions- used by Dalton, elements combined in fixed ratio when they react = masses of reactants
