CHEMISTRY 161

Chapter 2

proton, p 1.67262 × 10-27 kg +1.6022 × 10-19 C +1

electron, e 9.10939 × 10-31 kg -1.6022 × 10-19 C -1

neutron, n 1.67493 × 10-27 kg 0 0

Subatomic Particles(1897 – 1932)

2.3. Periodic System of the Elements

Mendeleev

(1869)

AtomicWeight

Element Property

6.9 Lithium active metal

9.0 Beryllium metal

10.8 Boron nonmetallic solid

12.0 Carbon nonmetallic solid

14.0 Nitrogen nonmetal, inactive gas

16.0 Oxygen nonmetal, active gas

19.0 Fluorine nonmetal, very active gas

23.0 Sodium very active metal, properties like Li

24.3 Magnesium active metal

27.0 Aluminum metal

28.1 Silicon nonmetallic solid

31.0 Phosphorous nonmetallic solid, properties like N

32.1 Sulfur nonmetallic solid, properties like O

35.5 Chlorine nonmetallic gas, properties like F

39.1 Potassium very active metal, properties like Na

40.1 Calcium active metal, properties like Mg

6.9

Liactive metal

9.0

Bemetal

10.8

Bnonmetallic

solid

12.0

Cnonmetallic

solid

14.0

Nnonmetal,

inactive gas

16.0

Ononmetal, active gas

19.0

Fnonmetal, very active

gas

23.0

Navery active metal,

chemical properties like Li

24.3

Mgactive metal

27.0

Almetal

28.1

Sinonmetallic

solid

31.0

Pnonmetallic

solid, chemical

properties like N

32.1

Snonmetallic

solid, chemical

properties like O

35.5

Clnonmetallic

gas, chemical properties like

F

39.1

Kvery active metal,

chemical properties like Na

40.1

Caactive metal,

chemical properties like

Mg

Mendeleev’s Periodic System

“The properties of the elements ….are in periodic dependence ….. on the atomic weights of the elements."

2.4. Atomic Number, Mass Number, Isotopes

AZ Xatomic number

(number of protons)

(number of electrons)

mass number

(number of protons plus neutrons)

Mendeleev 1869

“The properties of the elements ….are in periodic dependence ….. on the atomic weights of the elements."

Theory of the Atom

1897-1932

“The properties of the elements ….are in periodic dependence ….. on the

atomic weights of the atomic number."

Periodic System of the Elements

1.Periodic System of the Elements

1.1. periods, groups

1.2. metals, nonmetals, semimetals

atomic number, mass number

2. Combination of Atoms2.1. diatomics, polyatomics

2.2. neutrals, ions (cations, anions)

3. Quantificationchemical formula, empirical formula

Homework

Chapter 2, p. 43-53 problems, group 1 – 8 elements