Cem 141 exam 3 - Study guides, Class notes & Summaries

CEM 141 Final Exam pt 3 (Real Exam 3, Mock Exam 3, PP Lecture 26-35) (1)

Cem 141 Chapter 3 Origin of Atoms Exam Questions| Already answered| GRADED A+ in an infinitely dense moment 13.8 billion years ago, the Universe is born from a singularity. - ANSWER- The Big Bang Theory true - ANSWER-If thermal energy is spreading out it will eventually cool a mysterious particle/force accelerates the expansion. - ANSWER-Inflation after 380,00 years; loose electrons cool enough to combine with protons. The Universe becomes transparent to light. The microwave background b...

CEM 141 - Exam 2 questions and answers well illustrated. mole - correct answers.6.022 x 10^23 things number of particles that allows us to convert from the molecular to the macroscopic level limiting reactant/reagent - correct t of one of the reactants which limits how much product can be formed. smallest amount. percent yield - correct l/theoretical x 100 electromagnetic radiation - correct answers. wavelength - correct answers.The distance between two co...

3-D extended continuous network (shown on tables in notes in red); continuous materials have higher boiling and melting points than discrete -️️What are continuous materials? small atoms/molecules (shoes on tables in notes in black) -️️What are discrete materials? H2: LDF He: LDF Li: metallic bonds (no LDFs in metals) move metal cores relative to one another c: covalent -️️Using the table found on lecture 25 slide 13 what kinds of interactions must be overcome in order to melt...

they have similar causes: electrostatic attraction of the electron of one atom to the nucleus of the other - ANSWER-Similarities between LDF and Covalent Bond 1. magnitude of attraction 2. how the electrons are arranged in the new species formed by the interaction - ANSWER-Differences between LDF and Covalent Bond because valence electrons are attracted to the nuclei of other atoms - ANSWER-Why do bonds form between atoms? 1. valence electrons from one atom become attracted to the nucleus...

rapid expansion of the universe -️️Big Bang how long after the Big Bang was air created? -️️few minutes how long after the Big Bang were leptons (quarks, electrons) created? -️️1 picosecond how long after the Big Bang were protons and neutrons created? -️️1 microsecond how did matter and stars begin to form? -️️in clumps

Ionization Energy - energy required to remove an electron from an atom in the gas phase Left Side Electrons - have weaker attractions to remove electrons *easier to remove electrons from the left side of the table than the right side* Does it take MORE or LESS energy to remove an electron from Li than from Na? - MORE Why? Because as we move down a group, the orbitals become larger and weaker. While going across the effective nuclear charge increases. (holds onto the electrons tighter)