Exam 2 Prep
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
What trend occurs in atomic radius across a period from left to right?
Atomic radius decreases due to increasing effective nuclear charge (Zeff) pulling valence electrons closer.
What trend occurs in atomic radius down a group from top to bottom?
Atomic radius increases as electrons occupy higher principal quantum numbers (n), adding shells further from the nucleus.
What is an ion?
A charged atom.
What are cations?
Positively charged ions formed by losing electrons.
What are anions?
Negatively charged ions formed by gaining electrons.
How does the size of cations compare to their parent atoms?
Cations are smaller than their parent atoms due to increased Zeff and reduced electron-electron repulsion.
How does the size of anions compare to their parent atoms?
Anions are larger than their parent atoms due to decreased Zeff per electron and increased electron-electron repulsion.
What is effective nuclear charge (Zeff)?
The net attractive force felt by valence electrons.
What is ionization energy (IE)?
The energy required to remove an electron from a gaseous atom or ion.
What is the trend in ionization energy across a period?
Ionization energy increases due to smaller atomic size and higher Zeff.
What is the trend in ionization energy down a group?
Ionization energy decreases as valence electrons are further from the nucleus and experience more shielding.
What happens to successive ionization energies?
Removing each additional electron generally requires more energy, with large jumps when removing electrons from stable, closed-shell configurations.
What is electron affinity (EA)?
The energy change when an electron is added to an atom.
Which elements have large negative electron affinities?
Halogens, as they release energy when gaining an electron.
What are the main groups in the periodic table?
Group 1: Alkali metals, Group 2: Alkaline earth metals, Group 16: Chalcogens, Group 17: Halogens, Group 18: Noble gases.
What is allotropy?
Different structural forms of the same element with distinct properties.
Give an example of allotropes of carbon.
Diamond and graphite.
What is formal charge (FC)?
FC = (valence electrons) − (nonbonding electrons) − (number of bonds).
What is resonance in chemistry?
The concept of delocalized electrons in molecules that can be represented by multiple structures.
What types of anions does oxygen form?
Oxide (O2−), peroxide (O2^2−), and superoxide (O2^−).
What is oxidation?
The loss of electrons.
What is reduction?
The gain of electrons.
What is the trend in halogens down the group?
Melting/boiling point increases, density increases, atomic radius increases, ionization energy decreases.
What are noble gases known for?
Having stable electron configurations and being unreactive.