Chemistry Unit 2 Flashcards

Questions and Answers

What is electronegativity?

The ability of an atom in a molecule to attract shared electrons to itself.

What are ionic bonds?

Transferring electrons between a metal and a nonmetal.

What are covalent bonds?

Sharing electrons between two non-metals.

What characterizes a nonpolar covalent bond?

Electrons are shared equally. Signup and view all the answers

What is a polar covalent bond?

Electrons are shared unequally. Signup and view all the answers

What are metallic bonds?

Electrons are not associated with a single atom or molecule (delocalized electrons). Signup and view all the answers

What does bond polarity refer to?

The difference in electronegativity values of two elements. Signup and view all the answers

Atoms with high electronegativity will develop ___

a negative partial charge. Signup and view all the answers

Atoms with low electronegativity will develop _____

a positive charge. Signup and view all the answers

What do dipole arrows do?

Point towards the more electronegative atom. Signup and view all the answers

In P-Cl bonding, where does the partial positive charge reside?

On the phosphorus atom. Signup and view all the answers

F2 is more polar than H2 because fluorine has a higher electronegativity than hydrogen.

False Signup and view all the answers

What are chemical bonds?

The attraction between the nucleus of one atom and the electron of another. Signup and view all the answers

What are repulsion forces?

Forces between protons and between electrons. Signup and view all the answers

What are attraction forces?

Forces between protons and electrons. Signup and view all the answers

What defines ionic bonds?

Electrostatic attraction between a cation and anion. Signup and view all the answers

How can interactions between cations and anions be explained?

Using Coulomb's law. Signup and view all the answers

What is electrostatic attraction?

The attraction between positive and negative charges. Signup and view all the answers

When do ionic compounds conduct electricity?

A substance must have charged particles and particles must be free to move. Signup and view all the answers

Does a solid conduct electricity?

False Signup and view all the answers

Compare metals and ionic compounds in terms of electricity conduction:

Metals = Mobile valence electrons Ionic Compounds = Mobile charged particles Signup and view all the answers

What are alloys?

Combining two or more metallic elements. Signup and view all the answers

Match the types of alloys with their definitions:

Substitutional alloys = Atoms of comparable radii where one atom substitutes for another atom in the lattice. Interstitial alloys = Atoms of different radii where smaller atoms fill the spaces between larger atoms. Signup and view all the answers

Study Notes

Electronegativity and Bonding Types

Electronegativity defines an atom's capacity to attract shared electrons within a molecule.
Ionic bonds involve the transfer of electrons from a metal to a nonmetal.
Covalent bonds form through the sharing of electrons between two nonmetals.
Nonpolar covalent bonds occur when electrons are shared equally between atoms.
Polar covalent bonds arise when electrons are shared unequally, leading to partial charges.

Characteristics of Bonds

Metallic bonds feature delocalized electrons, not confined to individual atoms, creating a "sea of electrons."
Bond polarity is determined by the difference in electronegativity values of two bonded elements.

Charge Development

Atoms with high electronegativity acquire a negative partial charge.
Conversely, atoms with low electronegativity develop a positive charge.

Dipole Moments and Bonding Examples

Dipole arrows indicate the direction toward the more electronegative atom in a polar bond.
In phosphorus-chlorine (P-Cl) bonding, phosphorus carries a partial positive charge due to its lower electronegativity (2.5) compared to chlorine (3.0).
Claims that F2 is more polar than H2 are incorrect; both have the same difference in electronegativity (0), resulting in equal polarity.

Nature of Chemical Bonds

Chemical bonds result from the attraction between one atom's nucleus and another atom's electrons.
Repulsion forces stem from like charges (proton-proton, electron-electron), while attraction forces involve opposite charges (protons and electrons).

Ionic Bonding and Coulomb's Law

Ionic bonds are characterized by electrostatic attractions between cations and anions.
Coulomb's law explains interactions between charged ions, incorporating charge values and distances.

Conductivity of Ionic Compounds

Ionic compounds conduct electricity when they contain free-moving charged particles.
Solid ionic compounds do not conduct electricity; however, molten ionic compounds do.
Metals, with mobile valence electrons, conduct electricity differently than ionic compounds, which require mobile charged particles.

Alloys and Their Types

Alloys are formed by combining two or more metallic elements, enhancing their properties.
Substitutional alloys consist of atoms with comparable radii, substituting one for another in the lattice (e.g., brass).
Interstitial alloys involve atoms of differing radii, where smaller atoms occupy spaces within larger atoms, typically increasing strength (e.g., steel with carbon).

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Test your understanding of key chemistry terms in this Quiz on Electronegativity, Ionic Bonds, and Covalent Bonds. Perfect for reinforcing concepts on how atoms bond in molecules. Use these flashcards to enhance your study sessions and master the content.