Chem 1B Flashcards

Questions and Answers

What are periodic properties?

Properties whose values can be predicted based on the element's position on the periodic table.

What is the basis for the transmission of nerve signals?

Movement of ions across cell membranes.

In what directions are Na+ and K+ ions pumped across membranes through ion channels?

Na+ moves out, K+ moves in.

How do we represent orbitals?

Represented as a square, and the electrons in that orbital as arrows. The direction of the arrow represents the spin of the electron. Signup and view all the answers

What is electron configuration?

Describes how the electrons are distributed in the various atomic orbitals. Signup and view all the answers

What is the Pauli exclusion principle?

No two electrons in an atom can have the same four quantum numbers. Signup and view all the answers

What does each electron in a multielectron atom experience?

Both the attraction to the nucleus and the repulsion by other electrons in the atom. Signup and view all the answers

What is the effective nuclear charge?

Total amount of attraction that an electron feels for the nucleus. Signup and view all the answers

What happens when the electrons are closer to the nucleus?

The more attraction it experiences. Signup and view all the answers

The better an outer electron is at penetrating through the electron cloud of inner electrons...

The more attraction it will have for the nucleus. Signup and view all the answers

What is the Aufbau principle?

States that electrons are added to the lowest energy orbitals first before moving to higher energy orbitals. Signup and view all the answers

What is Hund's rule?

The most stable arrangement of electrons is the one in which the number of electrons with the same spin is maximized. Signup and view all the answers

What are the general rules for writing electron configurations?

<ol> <li>Electrons will reside in the available orbitals of the lowest possible energy. 2. Each orbital can accommodate a maximum of two electrons. 3. Electrons will not pair in degenerate orbitals if an empty orbital is available. 4. Orbitals will fill in the order indicated in the figure.</li> </ol> Signup and view all the answers

How can electron configurations of all elements except hydrogen and helium be represented?

Noble gas core. Signup and view all the answers

What are the valence electrons?

The outermost electrons of an atom. Signup and view all the answers

What are core electrons?

Electrons in lower energy shells. Signup and view all the answers

What are the main group elements (representative elements)?

Elements in Groups 1A through 7A. Signup and view all the answers

What group are the noble gases?

Group 8A, have completely filled p sub shells. Signup and view all the answers

What group are the transition metals?

Groups 3-12. Signup and view all the answers

What make up the f-block transition elements?

Lanthanides and actinides. Signup and view all the answers

What is the effective nuclear charge (Z-eff)?

The actual magnitude of positive charge that is 'experienced' by an electron in the atom. Signup and view all the answers

How does the value of the effective nuclear charge increase?

Increases steadily from left to right. Signup and view all the answers

What is the atomic radius?

Distance between the nucleus of an atom and its valence shell. Signup and view all the answers

How does the atomic radius increase?

Increases from top to bottom down a group. Signup and view all the answers

How does the atomic radius decrease?

Left to right across a period. Signup and view all the answers

What is the ionization energy (IE)?

Minimum energy required to remove an electron from an atom in the gas phase. Signup and view all the answers

What happens to the ionization energy as the Z-eff increases?

Ionization energy increases. Signup and view all the answers

Why is removing a paired electron easier?

Because of the repulsive forces between two electrons. Signup and view all the answers

Why does it take more energy to remove the second, third, fourth, and so on electrons?

Harder to remove an electron from a cation than an atom. Signup and view all the answers

What is electron affinity (EA)?

Negative of the energy released when an atom in the gas phase accepts an electron. Signup and view all the answers

How does electron affinity increase?

Like ionization energy; increases from left to right across a period. Signup and view all the answers

Is it easier to add an electron to an s orbital than to add one to a p orbital with the same quantum number?

True Signup and view all the answers

Characteristics of metals include:

Shiny, malleable, ductile, good conductors of both heat and electricity, low ionization energies, commonly form cations. Signup and view all the answers

Characteristics of nonmetals include:

Vary in color, not shiny, brittle, poor conductors of heat and electricity, high electron affinities, form anions. Signup and view all the answers

Characteristics of metalloids are:

Elements with properties intermediate between those of metals and nonmetals. Signup and view all the answers

What is the definition of isoelectronic?

Species with identical electron configurations to the noble gas to the right. Signup and view all the answers

What is the ionic radius?

Radius of a cation or an anion. Signup and view all the answers

What happens to the radius when an atom loses an electron to become a cation?

The radius decreases due in part to a reduction in electron-electron repulsions in the valence shell. Signup and view all the answers

What happens to the radius when an atom gains one or more electrons to become an anion?

The radius increases due in part to increased electron-electron repulsions. Signup and view all the answers

What is an isoelectronic series?

Series of two or more species that have identical electron configurations but different nuclear charges. Signup and view all the answers

How many valence electrons do the alkaline earth metals possess?

2 electrons. Signup and view all the answers

A cation of +2 indicates that an element has?

Lost 2 electrons. Signup and view all the answers

For a particular element, identify the species that has the smallest radius.

Cation Signup and view all the answers

Identify the elements correctly showing decreasing radii size.

N3- > N Signup and view all the answers

Place the following in order of increasing first ionization energy: N, F, As.

As, N, F. Signup and view all the answers

Give the electron configuration for O.

1s2 2s2 2p4. Signup and view all the answers

Of the following, which atom has the largest atomic radius?

Na Signup and view all the answers

Place the following in order of decreasing magnitude of lattice energy: K2O, Rb2S, Li2O.

Li2O, K2O, Rb2S. Signup and view all the answers

Identify the weakest bond.

Single covalent bond Signup and view all the answers

Give the number of valence electrons for XeI2.

22 valence electrons. Signup and view all the answers

A reaction is exothermic when:

Weak bonds break and strong bonds form. Signup and view all the answers

Identify an ionic bond.

Electrons are transferred Signup and view all the answers

Identify a bond with covalent bonding.

H2Se Signup and view all the answers

What is the Lewis theory?

Simplest bonding theories that emphasize valence electrons to explain bonding. Signup and view all the answers

What do Lewis structures allow us to predict?

Molecular stability, shape, size, and polarity. Signup and view all the answers

Why do chemical bonds form?

Chemical bonds form because they lower the potential energy between the charged particles that compose atoms. Signup and view all the answers

What types of atoms make up an ionic bond?

Metal and nonmetal; electrons transferred. Signup and view all the answers

What type of atoms make up a covalent bond?

Nonmetal and nonmetal; electrons shared. Signup and view all the answers

What type of atoms make up a metallic bond?

Metal and metal; electrons pooled. Signup and view all the answers

What happens when a metal atom loses electrons?

It becomes a cation. Signup and view all the answers

What happens when a nonmetal gains electrons?

It becomes an anion; nonmetals have high ionization energies. Signup and view all the answers

How many valence electrons do transition metals have?

Two valence electrons. Signup and view all the answers

Metals form _____ by losing valence shell electrons.

cations Signup and view all the answers

Nonmetals form ______ by gaining valence electrons.

anions Signup and view all the answers

For main group metals, the number of dots indicates:

The number of electrons that are lost. Signup and view all the answers

For nonmetals in the second period, the number of unpaired dots indicates:

The number of bonds the atom can form. Signup and view all the answers

What is lattice energy?

Amount of energy required to convert a mole of ionic solid to its constituent ions in the gas phase. Signup and view all the answers

What is electronegativity?

The ability of an atom to attract bonding electrons to itself; increases across a period and decreases down a group. Signup and view all the answers

If the difference in electronegativity between bonded atoms is 0, what type of bond is it?

Pure covalent. Signup and view all the answers

If the difference in electronegativity between bonded atoms is between 0.1-0.4, what type of bond is it?

Nonpolar covalent. Signup and view all the answers

If the difference in electronegativity between bonded atoms is 0.5-1.9, what type of bond is it?

Polar covalent. Signup and view all the answers

If the difference in electronegativity between bonded atoms is 2.0 or greater, what type of bond is it?

100% ionic. Signup and view all the answers

What is dipole moment?

Measure of bond polarity; material with a positive and negative end. Signup and view all the answers

What is formal charge?

Fictitious charge assigned to each atom in a Lewis structure that helps distinguish among competing Lewis structures. Signup and view all the answers

What is the sum of all formal charges in a molecule?

<ol start="0"> <li></li> </ol> Signup and view all the answers

What is bond energy?

The amount of energy it takes to break one mole of a bond in a compound; always positive, endothermic. Signup and view all the answers

Study Notes

Periodic Properties and Electron Configuration

Periodic properties are predictable based on an element's position in the periodic table.
Electron configuration describes the distribution of electrons in atomic orbitals.
The Pauli exclusion principle states that no two electrons can have identical quantum numbers.
Effective nuclear charge is the attraction experienced by electrons from the nucleus, increasing from left to right.

Ion Movement and Nerve Signals

Nerve signals are transmitted through the movement of ions across cell membranes, with Na+ ions moving out and K+ ions moving in.

Orbital Representation and Electron Rules

Orbitals are represented as squares, with electrons depicted as arrows; arrow direction indicates electron spin.
The Aufbau principle dictates filling the lowest energy orbitals first.
Hund's rule states that electrons fill degenerate orbitals singly before pairing.

Atomic and Ionic Sizes

Atomic radius is the distance from the nucleus to the valence shell, increasing down a group and decreasing across a period.
Cations are smaller than their parent atoms due to reduced electron-electron repulsions after losing electrons.
Anions are larger due to increased electron-electron repulsions after gaining electrons.

Ionization Energy and Electron Affinity

Ionization energy (IE) is the energy needed to remove an electron from an atom in the gas phase, increasing with effective nuclear charge.
Electron affinity (EA) is the energy change when an atom accepts an electron, also increasing across a period.

Bonds and Lattice Energy

Cations are formed by the loss of electrons, while anions are formed by the gain of electrons.
Ionic bonds involve the transfer of electrons between metals and nonmetals, whereas covalent bonds involve sharing electrons between nonmetals.
Lattice energy measures the energy required to separate ions in an ionic solid, always exothermic.

Electronegativity and Bond Types

Electronegativity is the ability of an atom to attract bonding electrons, increasing across a period and decreasing down a group.
Bond types vary based on the difference in electronegativity:
- 0 = pure covalent
- 0.1-0.4 = nonpolar covalent
- 0.5-1.9 = polar covalent
- ≥2.0 = ionic

Lewis Structures and Formal Charge

Lewis structures depict molecular stability and bonding characteristics, focusing on valence electrons.
Formal charge is a hypothetical charge used to assess potential resonance structures, with the sum in a neutral molecule being zero.

Key Atomic Concepts

Valence electrons are the outermost electrons that determine chemical reactivity.
Core electrons reside in inner shells and do not participate in bonding.
Transition metals typically have two valence electrons, unlike main group elements which vary.

Chemical Reactions

Exothermic reactions occur when weak bonds break and strong bonds form, releasing energy in the process.
Bond energy refers to the energy needed to break one mole of a bond, always positive.

This summary captures essential concepts and principles necessary for understanding chemical properties and behavior based on the provided flashcards.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on key concepts from Chemistry 1B with these flashcards. Topics include periodic properties, nerve signal transmission, and ion movement across membranes. Ideal for students looking to reinforce their understanding of chemical principles.