Transcript Kelter chapter 3 part 1

Chapter 3 - Part 1
3.1 Bonding
결합의 원리
What is Bonding?
• Forces that attract atoms or ions together
• Three Forces that affect Bonding
– Attraction between electrons and nuclei
– Repulsion between electrons
– Repulsion between nuclei
• Bonding Stabilizes Atoms (Lower Energy)
What is Special about Noble Gases?
• Noble Gases (He, Ne, Ar, Kr, Xe)
– non-reactive
– 8 electrons in outer shell
• Atoms form Ions
– to achieve 8 electrons in outer shell (octet)
Types of Bonding
• Ionic Bonding 이온 결합
– metals and non-metals
– bonds between ions
– each ion has a full outer shell
Types of Bonding
• Ionic Bonding
– metals and non-metals
– bonds between ions
– each ion has a full outer shell
• Covalent Bonding 공유 결합
– non-metals and non-metals
– electrons are shared between atoms
– each atom shares electron to fill outer shell
Types of Bonding
• Metallic Bonding
– between metals
– electrons are loosely bound
– electrons are shared and move freely from
atom to atom
Lewis Structures
•
Visualize Atoms and Electrons
• 원소기호는 원자를 표시
• 점은 전자를 표시
H
O
H
• 전자쌍 하나는 단일 결합을 나타내고 직선으로 표시
H OH
H O H
Lewis Dot Diagrams
Molecules
• Small Molecules
– 2-40 atoms simple molecules
– gases, solvents, amino acids, gasoline
• Medium Molecules
– 40-200 atoms
– steroids, fatty acids, cooking oil
• Large Molecules
– tens of thousands of atoms
– DNA, enzymes, proteins, polymers
Continuous Networks
• Covalent Networks
– trillions of atoms
– atoms are arranged in fixed lattice
• Ionic Solids
– trillions of ions (cations and anions)
– ions are arranged in fixed lattice