Chapter 5.2 – Exploring the Periodic Table

- periodic trends on the periodic table are due to electron arrangement- the number of valence electrons determines chemical properties- an elements location is related to its electron arrangement

s pd

f

sublevel being filled

Chapter 5.2 – Exploring the Periodic Table

- Group 1 and 2 fill the s sublevel- Group 1 has 1 valence electron- Group 2 has 2 valence electrons- Groups 13 – 18 fill the p sublevel, the s sublevel is filled- Group 13 has 3 valence electrons- Group 14 has 4 valence electrons- Group 15 has 5 valence electrons- Group 16 has 6 valence electrons- Group 17 has 7 valence electrons- Group 18 has 8 valence electrons

Chapter 5.2 – Exploring the Periodic Table

ion –

atom or molecule that has gained or lost one or more electrons and has a negative or positive charge

- ions do not have equal numbers of protons and electrons

- atoms want to fill their s and p sublevels and have 8 valence electrons

- atoms gain 8 valence electrons by gaining or losing electrons

cation – positive ion

anion – negative ion

Chapter 5.2 – Exploring the Periodic Table

- if an atom has 1, 2, or 3 valence electrons, the atom will lose electrons and form a positive ion

- if an atom has 5, 6, or 7 valence electrons, the atom will gain electrons and form a negative ion

Lithium (Li) –

Group 1 – has 1 valence electron –

forms Li+ ion

Oxygen (O) –

Group 16 – 6 valence electrons –

forms O2- ion

Chapter 5.2 – Exploring the Periodic Table

metal –

element that is shiny and conducts heat and electricity well

- found on the left side of the periodic table

- most elements are metals

nonmetal –

element that conducts heat and electricity poorly

- found on the right side of the periodic table

- most are gases

Chapter 5.2 – Exploring the Periodic Table

semiconductor or metalloid –

element that conducts electric current better than an insulator but not as well as a conductor

- shares properties with metals and nonmetals

- found between metals and nonmetals on the periodic table