Elements

Periodic Table

The periodic table organizes the Elements

Understanding the periodic table will help you learn about each of the 118 known elements.

Key to the Periodic Table

Element square

Identifies each known element

Symbol Name Atomic

Number Mass Number

Atomic Number

This refers to how many protons an atom of that element has.

No two elements, have the same number of protons.Bohr Model of Hydrogen Atom

Wave Model

Learning Check

State the number of protons for atoms of each of the following:A. Nitrogen 1) 5 protons 2) 7 protons 3) 14 protons

B. Sulfur 1) 32 protons 2) 16 protons 3) 6 protons

C. Barium1) 137 protons 2) 81 protons 3) 56 protons

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Solution

State the number of protons for atoms of each of the following:A. Nitrogen 2) 7 protons B. Sulfur

2) 16 protons

C. Barium3) 56 protons

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Atomic Mass

Atomic Mass refers to the “weight” of the atom.

Add the number of protons with the number of neutrons.

HThis is a helium atom. Its atomic mass is 4 (protons plus neutrons).

What is its atomic number?

Number of Neutrons

Mass Number – Atomic Number

Or Protons + Neutrons - Protons Number of Neutrons Because it’s and average Round the number

Virtual School Atomic and Mass Number

http://www.youtube.com/watch?v=_S7ov25y3_M&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

Learning Check

How Many Neutrons in 1. Cr Mass Number = 51.996

2. Fr Mass Number = 223

3. Mg Mass Numb er = 24.305

4. Si Mass Number = 28.086

Learning Check

How Many Neutrons in 1. Cr Mass Number = 51.996

27.996 2. Fr Mass Number = 223 136 3. Mg Mass Number = 24.305 12.305 4. Si Mass Number = 28.086 14.086

Number of Electrons

Number of protons = Number of electrons

Atomic number = Number of electrons

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Learning Check

How many electrons are in 1. K 2. Ca 3. Ba 4. O 5. Br

Learning Check How many electrons are in 1. K 19 2. Ca 20 3. Ba 56 4. O

8 5. Br 35

Isotopes

Atoms with the same number of

protons, but different numbers of

neutrons.

Isotopes of chlorine

35Cl 37Cl17 17

chlorine - 35 chlorine - 37

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Virtual School Isotopes

http://www.youtube.com/watch?v=xjY5p-1CDr8&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

Virtual School Example of Isotopes

http://www.youtube.com/watch?v=9d3NcxFG3RQ&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

Learning Check

Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C. State the number of protons, neutrons, and electrons in each of these carbon atoms.

12C 13C 14C 6 6 6

#p _______ _______ _______

#n _______ _______ _______

#e _______ _______ _______

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Solution

12C 13C 14C 6 6 6

#p 6 6

6

#n 6 7 8

#e 6 6

6

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Learning Check

An atom of zinc has a mass number of 65.

A. Number of protons in the zinc atom 1) 30 2) 35 3) 65

B. Number of neutrons in the zinc

atom 1) 30 2) 35 3) 65

C. What is the mass number of a zinc isotope

with 37 neutrons? 1) 37 2) 65 3) 67

LecturePLUS Timberlake 20

Solution

An atom of zinc has a mass number of 65.

A. Number of protons in the zinc atom 1) 30

B. Number of neutrons in the zinc

atom2) 35

C. What is the mass number of a zinc isotope

with 37 neutrons?3) 67

LecturePLUS Timberlake 21

Learning Check

Write the atomic symbols for atoms with the following:

A. 8 p+, 8 n, 8 e- ___________

B. 17p+, 20n, 17e- ___________

C. 47p+, 60 n, 47 e- ___________

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Solution

16OA. 8 p+, 8 n, 8 e- 8

B. 17p+, 20n, 17e- 37Cl 17

C. 47p+, 60 n, 47 e- 107Ag 47

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