Ch. 10 - Atomic Structure Structure of the Atom (p.270-271, 276-277) Chemical Symbols Subatomic Particles

Metal that forms bright blue solid compounds. Chemical Symbols Capitals matter! Element symbols contain ONE capital letter followed by lowercase letter(s) if necessary. Metal that forms bright blue solid compounds. Co vs. CO Poisonous gas.

Subatomic Particles in a neutral atom Most of the atom’s mass. NUCLEUS ELECTRONS in a neutral atom PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE Most of the atom’s mass. Atomic Number equals the # of...

Meet the “Atoms” Family! Atoms Family Album

ATOMIC NUMBER, #6 Atomic mass CHEMICAL SYMBOL = “C” element

Ch. 10 - Atomic Structure Electron Cloud Model (p.272-274) Orbital Energy Levels Bohr Model Diagrams

Orbital Region where there is 90% probability of finding an electron. Can’t pinpoint the location of an electron. Density of dots represents degree of probability.

Energy Levels Electrons can only exist at certain energy levels. Low energy levels are close to the nucleus.

Bohr Model Diagrams Simplified energy levels using Bohr’s idea of circular orbits. Can replace with: 3p 4n Lithium Atomic #: 3 Mass: 7 # of p: 3 # of e: 3 # of n: 4 e- e- p n Maximum e- Level 1 2e- Level 2 8e- Level 3 18e- Level 4 32e- e-

Bohr Diagram - Sodium e e e e e 11p e 12n e Maximum e- e e Level 1 2e-

Bohr Model Activity Choose a number between 1 & 18. Find your element by the atomic number you picked. Draw a Bohr Model diagram for your element on your marker board. Round off the mass listed on the table and subtract the atomic # to find the # of neutrons. Abbreviate the # of ‘p’ and ‘n’ in the nucleus. Have a partner check your drawing. Repeat with a new element.

Subatomic Particles p. 276-277 Quarks 6 types He 3 quarks = 1 proton or 1 neutron

Masses of Atoms (p.278-281) Atomic Mass Mass Number Isotopes Ch. 10 - Atomic Structure Masses of Atoms (p.278-281) Atomic Mass Mass Number Isotopes

Atomic Mass atomic mass unit (amu) 1 amu = 1/12 the mass of a 12C atom 1 proton = 1 amu 1 neutron = 1 amu 1amu = 1.67  10-24 g © Addison-Wesley Publishing Company, Inc.

Mass Number Sum of the protons and neutrons in the nucleus of an atom. © Addison-Wesley Publishing Company, Inc. Always a whole number. # of neutrons = mass # - atomic #

Calculate the # of P, N, and E of each of the following elements B, P=5 E=5 N=6 O, P=8 E=8 N=8 As, P=33 E=33 N=42

Isotopes Mass # Atomic # Atoms of the same element with different numbers of neutrons. Isotope symbol: Mass # Atomic # “Carbon-12”

Isotopes © Addison-Wesley Publishing Company, Inc.

Isotopes Average Atomic Mass reported on Periodic Table weighted average of all isotopes Avg. Atomic Mass

Isotopes EX: About 8 out of 10 chlorine atoms are chlorine-35. Two out of 10 are chlorine-37. Avg. Atomic Mass 35.4 u

I. History of the Periodic Table (p.284-285) Mendeleev Mosely Ch. 10 - The Periodic Table I. History of the Periodic Table (p.284-285) Mendeleev Mosely

Dmitri Mendeleev Dmitri Mendeleev (1869, Russian) Organized elements by increasing atomic mass. Predicted the existence of undiscovered elements.

Henry Mosely Henry Mosely (1913, British) Organized elements by increasing atomic number. Fixed problems in Mendeleev’s arrangement.

Organization (p.286-291) arrangement Rows & Columns Table Sections Ch. 10 - The Periodic Table Organization (p.286-291) arrangement Rows & Columns Table Sections

Arrangement Metals Nonmetals Metalloids

Columns & Rows Group (Family) Period

Atomic number = 6 Atomic Mass, 12 Chemical symbol Element Name

Periodic Trends (p.288-291) Terms Periodic Trends Dot Diagrams Ch. 10 - The Periodic Table Periodic Trends (p.288-291) Terms Periodic Trends Dot Diagrams

Terms Periodic Law Properties of elements repeat periodically when the elements are arranged by increasing atomic number.

Valence Electrons Valence Electrons e- in the outermost energy level Determine how an element will react.

Periodic Trends Atomic Radius Increases to the LEFT and DOWN.

Periodic Trends Group # = # of valence e- (except He) Families have similar reactivity. Period # = # of energy levels 1A 2A 3A 4A 5A 6A 7A 8A

Dot Diagrams Dots represent the valence e-. EX: Sodium EX: Chlorine