SDSU CHEMISTRY PLACEMENT TEST WITH COMPLETE SOLUTIONS 100% 2023/2024

SDSU CHEMISTRY PLACEMENT TEST WITH COMPLETE SOLUTIONS 100% 2023/2024 proton -heavy -positively charged -nucleon neutron -heavy -neutral -nucleon electron -very small (1/1800 of proton) -negative -outside of nucleus properties of nucleus -# of protons determines the element -held together by nuclear force -# of protons is extremely stable unlike # of electrons atomic number equal to the # of protons atomic mass # of protons + # of neutrons averaged across all of the element on earth isotopes -when elements have different masses but the same chemical properties -ex. silver-107 and silver-109 lewis dot -a 2-D model that represents covalent bonds as straight lines, ionic bonds as spaces, and unbonded valence electrons as dots -can have single, double, or triple bonds physical properties of compounds and molecules -melting point -boiling point -solubility -electrical conductivity molecular mass # of atoms(atomic mass)=molecular mass type (n)one of naming inorganic compounds -metal and nonmetal -cation anion-ide -ex. NaCl: Sodium Chloride type(II) of naming inorganic compounds -cation( ) anion-ide -ex. CuO: Copper(II) Oxide type tri of naming inorganic compounds -cation prefix anion-ide -ex. CO: Carbon Monoxide balancing equations -need an equal number of atoms on each side -ex. C12H22O11 + O2 --> CO2 + H2O C12H22O11 + 12O2 --> 12CO2 + 11H2O stoichiometry -measuring the chemicals that go into and come out of any given reaction -allows us to count atoms by weighing them AMU atomic mass unit mole - 6.022 x 10^23 -a mole of any element contains 6.022 x 10^23 atoms of that element no matter what -mass of a mole depends on the average mass of the element enthalpy -only interested in how much heat is going to change - H=E+PV -E: internal energy; P: pressure; V: volume entropy a measure of molecular randomness or disorder elctrostatic force -like charges repel -different charges attract bond length the distance between 2 nuclei at the point of minimum energy electronegativity