Exam (elaborations)
CEM EXAM 2 QUESTIONS AND ANSWERS WITH SOLUTIONS 2024
- Course
- Institution
CEM EXAM 2 QUESTIONS AND ANSWERS WITH SOLUTIONS 2024
[Show more]
Content preview
CEM EXAM 2 QUESTIONS ANDANSWERS WITH SOLUTIONS 2024
What are core electrons? - ANSWER Low in energy and close to the nucleus- within the closed shell
-A closed shell of electrons are very stable and don't participate in reactions
What are valence electrons? - ANSWER Higher in energy and outside of a closed shell
-These are the electrons that determine reactivity
Atomic radius - ANSWER Half the distance between the two nuclei
Does atomic radius increase or decrease down a group? - ANSWER Increase
Does atomic radius increase or decrease across a row? - ANSWER Decrease
What does the size of an atom depend on? - ANSWER 1. Attractions of the protons and electrons
2. Repulsions between the electrons in the atom
What state does the atomic radius represent? - ANSWER Where the forces of attraction between the
electrons and the protons are equal to the forces of repulsion between the electrons
Why does atomic radius decrease across a row? - ANSWER Effective nuclear charge. Atoms with a high
effective nuclear charge "hold onto their electrons" tightly. Maling the electrons more strongly attached
to the nucleus. Which is why atomic radius decreases across a row.
Effective nuclear charge - ANSWER Core electrons "cancel out" the positive charge from the same
number of protons
Each electron in the valence shell feels the effect of the protons that are left out. Atoms with a high
effective nuclear charge "hold onto their electrons" tightly. Maling the electrons more strongly attached
to the nucleus. Which is why atomic radius decreases across a row.
, Effective nuclear charge formula - ANSWER Z(enc)=z(actual nuclear charge[# protons])-S(# core
electrons)
T/F Effective nuclear charge increases across a row - ANSWER True
Ion - ANSWER Atoms in which electrons have been added or removed
If an electron is removed from an atom, what is the charge of the ion? - ANSWER Positive (the outermost
electron is removed resulting in a cation)
What is a cation? - ANSWER positively charged atom or molecule
What has a larger radius the atom or the cation of the atom? - ANSWER The regular atom because more
electrons means a greater electron electron repulsion
If an electron is added to an atom, what is the charge of the ion? - ANSWER Negative(an electron is
added to the next available (lowest energy) orbital
What is an anion? - ANSWER Negatively charged atom or molecule, it gained an electron
What has a larger radius the atom or the anion of the atom? - ANSWER The anion because you add an
electron which makes a greater electron electron repulsion
Ionization Energy - ANSWER nergy required to remove an electron from an atom in the gas phase
T/F Ionization energy decreases down a group/ column - ANSWER True
T/F Ionization energy increases across a row - ANSWER True
What are Ionization energies affected by? - ANSWER -Size of atom/ion(smaller size= higher IE)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Performance. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $16.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79271 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now