Inorganic Chemistry - Atomic Structure

Inorganic Chemistry - Atomic Structure

Biology 2121Chapter 2

Biology 2121Chapter 2

Introduction

• (1). Cells are the basic units of living organisms– Atoms ----- elements --- compounds (molecules)– Matter

• (2). Elements – 116 total (92 naturally occuring)– 96% of body (C,O,H,N)

• 20 trace elements

• (3). Inorganic vs Organic Chemistry

Atomic Structure

• (1). What are atoms made of?– Nucleus (protons and neutrons)– Energy levels (electrons)

• (2). Properties– Neutrons (0, 1 amu)– Proton (+1, 1 amu)– Electron (-1, 1/2000 amu)– Marieb link

Elements and the Periodic Chart

• (1). Metals and Nonmetals

• (2). Atomic Number– Protons

• (3) Mass Number – Protons + electrons– Mass of the atom!

Elements and the Periodic Chart

Average Atomic Mass and Isotopes

• What are isotopes? – Same type of atoms with differing numbers of

neutrons.– Average of all isotopes • Average atomic mass number• Not all isotopes –equal amounts

Valance Electrons and Planetary Models

• (1). Valance electrons – Outer shell electrons– Involved in bonding

• (2). Drawing Planetary Models of atoms – Periodic chart (appendix C)

Valence Shells

Why are valence electrons important?

• Valence electrons are involved in bonding

• Electrons – Transferred from one atom to another– Shared between atoms