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Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They...
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Transcript of Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They...
![Page 1: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/1.jpg)
Unit 6A: Ionic and Covalent
Bonding
![Page 2: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/2.jpg)
IonsWhy do elements in the same group behave similarly?• They have the same number of valence electrons.
Valence electrons are the electrons in the highest occupied energy level of an element’s atoms.
How do you find the number of valence electrons in an atom of a representative element? • The Group number.
![Page 3: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/3.jpg)
IonsWhat are electron dot structures?• Diagrams that show valence electrons as dots.
![Page 4: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/4.jpg)
IonsWhy do atoms form ions?• In order to become more stable
The octet rule states that in forming compounds, atoms tend to achieve the electron configuration of a noble gas.
How do metals become stable?• By losing their valence electrons
How do nonmetals become stable?• By gaining valence electrons• By sharing valence electrons with other nonmetals
![Page 5: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/5.jpg)
IonsHow are cations formed?• Cations are formed when an atom loses one or
more electrons.
![Page 6: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/6.jpg)
IonsHow are anions formed?• Anions are formed when an atom gains one or
more valence electrons.
![Page 7: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/7.jpg)
Ionic Bonds and Ionic Compounds
What is an ionic compound?• A compound that is composed of cations and
anions.
What is the electrical charge of an ionic compound?• All ionic compounds are neutral
What is an ionic bond?• The electrostatic forces that hold cations and
anions together in an ionic compound.
![Page 8: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/8.jpg)
Ionic Bonds and Ionic Compounds
How do chemists represent the composition of a substance?
A chemical formula shows the kinds and numbers of atoms in the smallest unit of a substance.
Examples:• H2O
• C12H22O11
• Fe2O3
• CO2
![Page 9: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/9.jpg)
Ionic Bonds and Ionic Compounds
The smallest unit of an ionic compound is called a formula unit. • Lowest whole-number ratio of ions in an ionic
compound
Examples:Sodium chloride• NaCl
Magnesium chloride• MgCl2
![Page 10: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/10.jpg)
Molecular CompoundsWhy do atoms form molecular compounds?• To satisfy the octet rule
How are atoms held together in covalent bonds?• Sharing of valence electrons
![Page 11: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/11.jpg)
Molecular CompoundsWhat is a molecular formula?• The chemical formula of a molecular compound• It shows how many atoms of each element a
molecule contains
Examples:• H2O
• CO2
• NH3
![Page 12: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/12.jpg)
MoleculesDiatomic Molecule: A molecule consisting of only two atoms.
There are seven diatomic elements:• Hydrogen (H2)
• Oxygen (O2)
• Nitrogen (N2)
• Fluorine (F2)
• Chlorine (Cl2)
• Bromine (Br2)
• Iodine (I2)
![Page 13: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/13.jpg)
The Nature of Covalent Bonding
Single Covalent Bond
An electron dot structure represents a covalent bond using dots to represent the shared pair of electrons.
![Page 14: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/14.jpg)
The Nature of Covalent Bonding
Unshared Electrons• A pair of electrons not shared between atoms is
called an unshared pair of electrons
A structural formula represents covalent bonds by dashes and shows the arrangement of covalently bonded atoms.
![Page 15: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/15.jpg)
The Nature of Covalent Bonding
Double Covalent Bond
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The Nature of Covalent Bonding
Triple Covalent Bond
![Page 17: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/17.jpg)
The Nature of Covalent Bonding
![Page 18: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/18.jpg)
Polar Bonds and Molecules
Polar Covalent Bond
A polar covalent bond is a covalent bond in which the electrons are shared unequally.
The more electronegative atom attracts electrons more strongly and gains a slightly negative charge. The less electronegative atom has a slightly positive charge.
![Page 19: Unit 6A: Ionic and Covalent Bonding. Ions Why do elements in the same group behave similarly? They have the same number of valence electrons. Valence.](https://reader035.fdocuments.us/reader035/viewer/2022070413/5697bfec1a28abf838cb8a44/html5/thumbnails/19.jpg)
Polar Bonds and Molecules
Differences Between Types of Bonds
Electronegativity Difference
Bond Type
Element Types
Examples
0 – 0.4NonpolarCovalent
Nonmetal-nonmetal
H―HCl―Cl
0.5 – 2.0Polar
CovalentNonmetal-nonmetal H―Cl
> 2.0 IonicMetal-
nonmetal Na+ Cl–