INTRODUCTION TO THE PERIODIC TABLE Atomic Number Symbol

INTRODUCTION TO THE PERIODIC TABLE Atomic Number ● Symbol ● Atomic Weight Element ● Compound ● Mixture

Atomic Theory l Atoms are building blocks of elements l Similar atoms in each element l Different from atoms of other elements l Two or more different atoms bond in simple ratios to form compounds Lecture. PLUS Timberlake 2

I am Dmitri Mendeleev! I made the PERIODIC TABLE !

What is the PERIODIC TABLE? o o Shows all known elements in the universe. Organizes the elements by chemical properties.

How do you read the PERIODIC TABLE?

What is the ATOMIC NUMBER? o o The number of protons found in the nucleus of an atom Or The number of electrons surrounding the nucleus of an atom.

What is the SYMBOL? o An abbreviation of the element name.

What is the ATOMIC WEIGHT? o The number of protons and neutrons in the nucleus of an atom.

How do I find the number of protons, electrons, and neutrons in an element using the periodic table? o # of PROTONS o # of ELECTRONS = ATOMIC NUMBER o = ATOMIC NUMBER # of NEUTRONS = ATOMIC _ ATOMIC WEIGHT NUMBER

Subatomic Particles Particle Symbol Charge Electron e- 1 - 0 Proton p+ + 1 Neutron n 0 1 Lecture. PLUS Timberlake Relative Mass 10

Location of Subatomic Particles 10 -13 cm electrons nucleus protons neutrons 10 -8 cm Lecture. PLUS Timberlake 11

Atomic Number Counts the number of protons in an atom Lecture. PLUS Timberlake 12

Periodic Table l Represents physical and chemical behavior of elements l Arranges elements by increasing atomic number l Repeats similar properties in columns known as chemical families or groups Lecture. PLUS Timberlake 13

Properties of Metals appear to the left of the dark ziz-zag line on the periodic table. Most metals are solid at room temperature.

Atomic Number on the Periodic Table Atomic Number Symbol 11 Na Lecture. PLUS Timberlake 15

All atoms of an element have the same number of protons 11 protons Sodium 11 Na Lecture. PLUS Timberlake 16

Learning Check AT 1 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 C. Barium 1) 137 protons Lecture. PLUS 2) 81 Timberlake protons 3) 56 17

Solution AT 1 State the number of protons for atoms of each of the following: A. Nitrogen 2) 7 protons B. Sulfur 2) 16 protons C. Barium 3) 56 protons Lecture. PLUS Timberlake 18

Number of Electrons l l An atom is neutral The net charge is zero Number of protons = Number of electrons Atomic number = Number of electrons Lecture. PLUS Timberlake 19

Mass Number Counts the number of protons and neutrons in an atom Lecture. PLUS Timberlake 20

Atomic Symbols l Show the mass number and atomic number l Give the symbol of the element mass number 23 Na atomic number sodium-23 11 Lecture. PLUS Timberlake 21

More Atomic Symbols 16 31 65 8 15 30 O 8 p+ 8 n 8 e- P 15 p+ 16 n 15 e- Zn 30 p+ Lecture. PLUS Timberlake 35 n 30 e- 22

Isotopes l Atoms with the same number of protons, but different numbers of neutrons. l Atoms of the same element (same atomic number) with different mass numbers Isotopes of chlorine 35 Cl 37 Cl 17 17 chlorine - 35 chlorine - 37 Lecture. PLUS Timberlake 23

Learning Check AT 2 Naturally occurring carbon consists of three isotopes, 12 C, 13 C, and 14 C. State the number of protons, neutrons, and electrons in each of these carbon atoms. 12 C 6 13 C 6 14 C 6 #P _______ #N _______ #E _______ Lecture. PLUS Timberlake 24

Solution AT 2 12 C 6 13 C 6 14 C 6 #P __6___ ___6___ #N __6___ _ _7___ ___8___ #E __6___ ___6___ Lecture. PLUS Timberlake 25

Learning Check AT 3 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 Lecture. PLUS Timberlake 26

Solution AT 3 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 atom 2) 35 C. What is the mass number of a zinc isotope with 37 neutrons? 3) 67 Lecture. PLUS Timberlake 27

Learning Check AT 4 Write the atomic symbols for atoms with the following: A. 8 p+, 8 n, 8 e- ______ B. 17 p+, 20 n, 17 e- ______ C. 47 p+, 60 n, 47 e- ______ Lecture. PLUS Timberlake 28

Solution AT 4 16 O A. 8 p+, 8 n, 8 e. B. 8 37 Cl 17 p+, 20 n, 17 e 17 C. 47 p+, 60 n, 47 e- 107 Ag 47 Lecture. PLUS Timberlake 29

Learning Check AT 5 An atom has 14 protons and 20 neutrons. A. Its atomic number is 1) 14 2) 16 3) 34 B. Its mass number is 1) 14 2) 16 3) 34 C. The element is 1) Si 2) Ca 3) Se D. Another isotope of this element is 1) 34 X 2) 34 X 3) 36 X 16 14 Lecture. PLUS Timberlake 14 30

Solution AT 5 An atom has 14 protons and 20 neutrons. A. It has atomic number 1) 14 B. It has a mass number of 3) 34 C. The element is 1) Si D. Another isotope of this element would be 3) 36 X 14 Lecture. PLUS Timberlake 31