# CH.2 d-h - Predicting Properties from the Periodic Table

The student will investigate and understand that the placement of elements on the periodic table is a function of their atomic structure. The periodic table is a tool used for the investigations of:
d) families or groups;
e) periods;
f) trends including atomic radii, electronegativity, shielding effect, and ionization energy;
g) electron configurations, valence electrons, and oxidation numbers;
h) chemical and physical properties.

Bloom's Levels:  Analyze; Understand

### BIG IDEAS

• The structure of an atom determines its properties.
• The organization of the periodic table is based on properties of the elements.
• Atoms are composed of smaller particles.

• I can explain why certain compounds form and others don't.
• I can explain why some reactions are explosive.

### UNDERSTANDING THE STANDARD

• The names of the groups on the periodic chart are alkali metals, alkaline earth metals, transition metals, halogens, and noble gases.
• Metalloids have properties of metals and nonmetals. They are located between metals and nonmetals on the periodic table. Some are used in semiconductors.
• Periods and groups are named by numbering columns and rows. Horizontal rows called periods have predictable properties based on an increasing number of electrons in the outer energy levels. Vertical columns called groups or families have similar properties because of their similar valence electron configurations.
• Electron configuration is the arrangement of electrons around the nucleus of an atom based on their energy level.
• electrons are added one at a time to the lowest energy levels first (Aufbau Principle). Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results (Hund's Rule).
• Energy levels are designated 1-7. ORbitals are designated s, p, d, and f according to their shapes and relate to the regions of the Periodic Table. An orbital can hold a maximum of two electrons (Pauli Exclusion Principle).
• Atoms can gain, lose, or share electrons within the outer energy level.
• Loss of electrons from neutral atoms results in the formation of an ion with a positive charge (cation). Gain of electrons by a neutral atom results in the formation of an ion with a negative charge (anion).
• Transition metals can have multiple oxidation states.
• The Periodic Law states that when elements are arranged in order of increasing atomic numbers, their physical and chemical properties show a periodic pattern
• Periodicity is regularly repeating patterns or trends in the chemical and physical properties of the elements arranged in the periodic table.
• Physical properties refer to the condition or quality of a substance that can be observed or mreasured without changing the substance's composition. I mportant physical properties are density, conductivity, melting point, boiling point, malleability, and ductility.
• Chemical properties refer to the ability of a substance to unergo chemical reaction and form a new substance.
• Reactivity is the tendency of an element to enter into a chemical reaction.

### ESSENTIALS

In order to meet this standard, it is expected that students will

d, e) distinguish between a group and a period.

identify key groups, periods, and regions of elements on the periodic table.

f) identify and explain trends in the periodic table as they relate to ionization energy, electronegativity, shielding effect, and relative sizes.

compare an element’s reactivity to the reactivity of other elements in the table.

g) relate the position of an element on the periodic table to its electron configuration.

determine the number of valence electrons and possible oxidation numbers from an element’s electron configuration.

write the electron configuration for the first 20 elements of the periodic table.

h) distinguish between physical and chemical properties of metals and nonmetals.

differentiate between pure substances and mixtures and between homogeneous and heterogeneous mixtures.

### KEY VOCABULARY

actinide series, allotrope, diagonal relationship, ferromagnetism, lanthanide series, metallury, mineral, ore

Updated: Dec 01, 2017