Day 25 – Daily Starter Calculate the formula mass for the following molecules: NaCl (NH4)3PO4

I. History of the Periodic Table (p.284-285) Mendeleev Mosely

A. Dmitri Mendeleev Dmitri Mendeleev (1869, Russian) Organized elements by increasing atomic mass. Predicted the existence of undiscovered elements.

B. Henry Mosely Henry Mosely (1913, British) Organized elements by increasing atomic number. Fixed problems in Mendeleev’s arrangement.

The Periodic Table II. Organization (p.286-291) Metallic Character Columns & Rows Table Sections

A. Metallic Character Metals Nonmetals Metalloids

B. Table Sections Representative Elements Transition Metals Inner Transition Metals

C. Columns & Rows Group (Family) Period

III. Periodic Trends (p.288-291) Terms Periodic Trends Dot Diagrams The Periodic Table III. Periodic Trends (p.288-291) Terms Periodic Trends Dot Diagrams

A. Terms Valence Electrons Atomic Radius First Ionization Energy e- in the outermost energy level Atomic Radius First Ionization Energy energy required to remove an e- from a neutral atom

B. Periodic Trends Atomic Radius Increases to the LEFT and DOWN.

B. Periodic Trends Increasing ionization energy Increases to the RIGHT and UP.

B. Periodic Trends N or Bi Ba or Ne Which atom has the higher 1st I.E.? (Use your Marker Board) N or Bi Ba or Ne

B. Periodic Trends N or Bi Ba or Ne N Ne Which atom has the higher 1st I.E.? N or Bi Ba or Ne N Ne

B. Periodic Trends Be or Ba Ca or Br Which atom has the larger radius? (Use your Marker Board) Be or Ba Ca or Br

B. Periodic Trends Be or Ba Ca or Br Ba Ca Which atom has the larger radius? Be or Ba Ca or Br Ba Ca

B. Periodic Trends Group # = # of valence e- (except He) Families have similar reactivity. Period # = # of energy levels 1A 2A 3A 4A 5A 6A 7A 8A

Valence electrons The electrons on the outer-most orbital Valence electrons of one atom combine with valence electrons of other atom(s) to form chemical bonds. The number of valence electrons of an element is determined by its periodic table group (vertical column)

C. Dot Diagrams Dots represent the valence e-. EX: Sodium EX: Chlorine

Remember…TOMORROW Atomic structure and symbols QUIZ 28 biochemical elements You will need to know the names of elements if given the symbol or vice versa You should be familiar with atomic structure, and… The concept of isotopes and finding the # of neutrons if given mass and number