Atomic Theory & Periodicity Flashcards
Chemistry Definition; Types of Chemistry
-The study of matter and the changes it undergoes
-Physical Chemistry: Understand chemical systems from a theoretical framework; lots of theory & math
-Analytical Chemists: Study methods for identification and quantification of matter within a chemical system; applied
-Inorganic: Study substances derived from all elements EXCEPT CARBOB
-Organic: Study Carbon based elements
-Biochemists: Chemical processes that occur within living systems
Matter Definition; Types of Matter
- Anything that has mass and occupies space
Solid: Molecules are densely packed, definite shape, not easily compressible
Liquids: Moles are loosely packed, no definite shape, not easily compressible
Gas: Molecules are not packed, no definite shape, easily compressible
Atoms & Molecules
Atoms: Submicroscopic particles that are the fundamental building blocks of all matter
-Protons: Positively charged particle, sizable mass (# of protons =Atomic #)
-Neutrons: Electrically neutral particle with a mass approx. equal to proton (# of neutrons determines which isotope)
-Electrons: Negatively charged particle with very small mass)
Molecules: Two or more atoms joined in a specific arrangement
Classification of matter: Composition
Pure Substance, Mixture
-Pure Substance: Single molecule
–> Element: Fundamental substance, cannot be broken down into simpler substances
–> Compound: Composed of two or more elements in fixed proportions; can only be separated by chemical method
-Mixture: Matter consisting of two or more pure substances that maintain their individual identities; can be separated by physical methods
–> Homogenous: Uniform composition; looks the same (solution)
–> Heterogenous: Not uniform; does not look the same
Changes in Matter
-Physical Change: A change that alters the state or appearance. Melting, freezing, vaporization, condensation, deposition (gas to a solid; frost), sublimation (solid to a gas; dry ice)
-Chemical Change: Change that alters composition
Atomic Theory
-John Dalton; 1808
-Each element is composed of tiny, indestructible particles called atoms
-All atoms of a given element have the same mass & other properties that distinguish them from atoms of other elements
-Atoms combine in simple, whole number ratios to for compounds
-Atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms change the way they are bound to each other
Atomic Structure; Electron Types
-Protons & Neutrons are bound together by strong nuclear forces into a dense structure called the nucleus
-Electrons are bound to the nucleus by electromagnetic forces
Core: tightly bound to nucleus, are not involved in chemical bonding
Valence: Not held as tightly, involved in chemical bonding
Periodic Table Groups
Main Group: 1-2, 13-18
Transition Metals: 3-12
Alkali Metals: 1
Alkali Earth Metals: 2
Halogens: 17
Noble Gases: 18
Atomic Number, Atomic Mass, Electron #
Atomic #: Number of protons in an element
Atomic Mass#: Number of protons and neutrons
Isotopes are identified by their atomic mass #
Group number gives us the number of valence electrons. Groups 13-18, subtract 10
