Chapter 6: Ionic and Molecular Compounds

electrons

The ________ in a nonpolar covalent molecule are distributed symmetrically.

metals Sn

The ________ and Pb in Group 4A lose electrons to form positive ions.

compounds

Most of the elements, except the noble gases, are found in nature combined as ____.

Electrons

________ may accumulate more in one part of the molecule than another, which forms a temporary dipole.

valence electron energy

One explanation for the stability of noble gases is that they have a filled ______ level.

octet

In the formation of either an ionic bond or a covalent bond, atoms lose, gain, or share valence electrons to acquire an *_______* of eight valence electrons.

Octet Rule

The tendency of atoms to attain a stable electron arrangement provides a key to our understanding of the ways in which atoms bond and form compounds.

Ionic Bonds

Occurs when the valence electrons of atoms of a metal are transferred to atoms of nonmetals.

Octet Rule

The tendency of atoms to attain a stable electron arrangement provides a key to our understanding of the ways in which atoms bond and form compounds

Ionic Bonds

Occurs when the valence electrons of atoms of a metal are transferred to atoms of nonmetals

Covalent Bonds

Occurs when atoms of nonmetals share valence electrons

Positive Ions

The loss of electrons

Ionic Charge

A positive electrical charge

Cations

Positively charged ions

Negative Ions

The gain of electrons

Anion

A negatively charged ion

The elements in Group 7A gain one electron to form ions with a 1

charge

The elements in Group 6A gain two electrons to form ions with a 2

charge

The elements in Group 5A gain three electrons to form ions with a 3

charge

Ionic Bonds

The ions are held together by strong electrical attractions between the oppositely charged ions

Formula Unit

The lowest ratio of the ions in an ionic compound

Examples

Potassium iodide, Magnesium bromide & Aluminum oxide

Polyatomic ion

A group of covalently bonded atoms that has an overall ionic charge

Molecular Compound

It contains two or more nonmetals that form covalent bonds

Double Bond

It occurs when two pairs of electrons are shared

Triple Bond

It occurs when three pairs of electors are shared

Nonpolar Covalent Bonds

A bond between atoms with identical or very similar electronegativity values

Polar Covalent Bond

Occurs when bonds are between atoms with different electronegativity values, and the electrons are shared unequally

Dipole

A polar covalent bond that has a separation of charges

Covalent Bonds

Occurs when atoms of nonmetals share valence electrons.

Positive Ions

The loss of electrons.

stable electron arrangement

In ionic bonding, ions form when atoms lose or gain electrons to form a _____.

Ionic Charge

A positive electrical charge.

Cations

Positively charged ions.

Negative Ions

The gain of electrons.

nonmetal

In an ionic compound, a ____ atom gains one or more valence electrons to obtain a stable electron configuration.

Anion

A negatively charged ion.

Group 1A

The elements in _____ lose one electron to form ions with a 1+ charge.

Group 2A

The elements in _____ lose two electrons to form ions with a 2+ charge.

Group 3A

The elements in _____ lose three electrons to form ions with a 3+ charge.

Group 7A

The elements in _____ gain one electron to form ions with a 1– charge.

Group 6A

The elements in _____ gain two electrons to form ions with a 2– charge.

Group 5A

The elements in _____ gain three electrons to form ions with a 3– charge.

Group 4A

The nonmetals of _____ 1142 do not typically form ions.

Ionic Bonds

The ions are held together by strong electrical attractions between the oppositely charged ions.

positive ions

This ions are formed by metals losing electrons

Negative Ions

These ions are formed when nonmetals gain electrons.

chemical formula

The ____ of a compound represents the symbols and subscripts in the lowest whole-number ratio of the atoms or ions.

subscripts

The _____ in the formula of an ionic compound represent the number of positive and negative ions that give an overall charge of zero.

Formula Unit

The lowest ratio of the ions in an ionic compound.

Polyatomic ion

A group of covalently bonded atoms that has an overall ionic charge.

covalent bond

When atoms share electrons, the bond is a _____.

molecule

When two or more atoms share electrons, they form a ____.

bonding pairs

The ______, are shown as two dots or a single line between atoms.

Double Bond

It occurs when two pairs of electrons are shared.

Triple Bond

It occurs when three pairs of electors are shared.

electronegativity

The _____ of an atom is its ability to attract the shared electrons in a chemical bond.

Fluorine

_____ has the highest electronegativity which has a value of 4.0.

Metal Cesium

_____ has the lowest electronegativity which has a value of 0.7.

Nonpolar Covalent Bonds

A bond between atoms with identical or very similar electronegativity values.

Polar Covalent Bond

Occurs when bonds are between atoms with different electronegativity values, and the electrons are shared unequally.

Dipole

A polar covalent bond that has a separation of charges.

Valence shell electron-pair repulsion (VSEPR) theory

The electron groups are arranged as far apart as possible around the central atom to minimize the repulsion between their negative charges.

minimal repulsion

According to VSEPR theory, ______ occurs when two electron groups are on opposite sides of the central C atom.

Linear electron-group

This gives the CO2 molecule a *_____* geometry and a linear shape with a bond angle of 180°.

trigonal planar

Minimal repulsion occurs when three electron groups are as far apart as possible around the central C atom, which gives 120° bond angles. This type of electron-group geometry is ____.

tetrahedral

When there are four atoms attached to four electron groups, the shape of the molecule is _____.

Nonpolar Molecule

* It also occurs when polar bonds cancel each other because they are in a symmetrical arrangement.

Polar Molecules

• One end of the molecule is more negatively charged than the other end.

• It occurs when the dipoles from the individual polar bonds do not cancel each other.

Dipole-Dipole Attractions

These are attractive forces that occur between the positive end of one molecule and the negative end of another.

Hydrogen Bonds

These occur between the partially positive hydrogen atom in one molecule and the partially negative nitrogen, oxygen, or fluorine atom in another molecule.

Dispersion Forces

• These are very weak attractions that occur between nonpolar molecules.

• The electrons in a nonpolar covalent molecule are distributed symmetrically.

temporary dipole

Electrons may accumulate more in one part of the molecule than another, which forms a ______.