Chem 2 Study Guide Summary PDF

# Final Study Guide ## Chem ### Matter & periodic table - Models of the atom - (Dalton, Thompson, Rutherford, Bohr) - Dalton - came up with atomic theory: 1. All matter made up of small particles, atoms. 2. Atoms can't be created, destroyed, or divided into smaller particles 3. A...

# Final Study Guide ## Chem ### Matter & periodic table - Models of the atom - (Dalton, Thompson, Rutherford, Bohr) - Dalton - came up with atomic theory: 1. All matter made up of small particles, atoms. 2. Atoms can't be created, destroyed, or divided into smaller particles 3. Atoms of different elements have different mass/size. 4. Compounds formed when atoms of different elements are combined. 5. Chemical reactions change the way atoms are grouped, DO NOT change atoms themselves. - Thompson - thought atoms consisted of: - Charges embedded in a sphere of positive - (Raisin bun model) - Cloud of + charge - Charges = electrons - Used a beam at gold foil, some went through, some were deflected, and some bounced back. - Suggested more + particles in atoms. - Rutherford - Based on Gold foil experiment - Dense, + nucleus in center, had particles called protons, 1 single positive charge. - Electrons are smaller than protons and orbit the nucleus, particles since - charge are electrons. - Empty space in which electrons exist. - Neutrons: same mass as proton, no charge. - Bohr - Described energy levels of electrons - electrons only exist in levels, not between. Max number of electrons on each level. - 2, 8, 8, 18, 18 - Lewis dot - Valence electrons ### Important Groups & General Characteristics - Groups in columns, periods in rows. - Metals - Shiny, conductors, ductile - Nonmetals - Non conductive, vary in state, color, reactivity. - Metalloids - along “semicircle” - Group 1/Alkaline Metals - Reactive with water, soluble. - Group 2/Alkaline Earth Metals - not soluble. - Group 17/Halogens - very reactive - Group 18/Noble Gases - unreactive. ### Compounds - Covalent/Ionic Bonds - **Covalent Bonds** (Share) - Occurs in non-metals, elements share electrons between them instead of transferring electrons to each other. - **Ionic Bonds** (Transfer) - Metals transfer elections to non-metals, producing ions. - Opposing charges cause them to attract each other. - **Polyatomic** (Transfer) - Formation: when formed, resulting ions have an electron configuration identical to the nearest noble gas (completed valence shells) are stable. - Ions of compounds form crystal lattice in which they are arranged. - Properties: solid with crystal shape (crystal lattice), high melting points, do not conduct electricity when dissolved in water, they become electrolytes (ions freely moving in solution and conduct electricity) are soluble. - **Molecular Compounds** (Share) - Formation: achieves electron configuration to nearest noble gas. - Properties: irregular shapes, low melting point, forces are weak (intermolecular forces), but once melted, forces become strong (intramolecular forces) - Non-electrolytes, low solubility. - Inter vs Intramolecular bonds - Intra: Ionic & Covalent bonds (Single molecule) - Inter: Between different molecules ### Naming - Treat polyatomics as one, DO NOT spilt up - end in “ate” or “ite” - Molecular compounds: 1. Write name of first element. 2. Write second with suffix “ide” 3. Use prefixes from subscripts, - Formula: 1. Write symbol first element. 2. Write symbol second element. 3. Add # that correspond to prefixes. - NO REDUCE - Ionic Compounds: 1. Write name of first element. 2. Write name of second element, suffix “ide” - NO PREFIXES - Formula: 1. Write symbol first element for polyatomic. 2. Write symbol second element for polyatomic. 3. Write cation/anion charges, superscripts beside symbols. 4. Loss over charges and write subscripts. 5. Reduce if possible.