10 28 how many electrons do atoms gain lose

Launch: 10/28   Grab your binder and immediately take a seat

  Place homework (storybook) on desk

  Partner on left, read your story book   Partner on right, just listen

  Switch!

What do atoms form ions? Mr. Heffner 10/28/09

Why do atoms form ions?   Want to be stable (like noble gases)

  Octet rule: 8 valence electrons

  Form ionic bonds to get 8   metals lose electrons cations (+)   nonmetals gain electrons anions (–)

Cation Anion

What ions do atoms form?   A three-step process for predicting ions:

  Step #1: metal or nonmetal?   Step #2: how far from the noble gases?

  Step #3: write out the symbol and charge

Example: In an ionic bond, what ion would Cl form?

  Step #1: metal or nonmetal?

What ions do atoms form?

Metals

Example: In an ionic bond, what ion would Cl form?

  Step #1: metal or nonmetal?   nonmetal = anion (–)   gain electron

What ions do atoms form?

Example: In an ionic bond, what ion would Cl form?

  Step 2: how far away from the noble gases?

What ions do atoms form?

only 1 space away

Example: In an ionic bond, what ion would Cl form?

  Step #3: write out the symbol and charge   Step #1: anion (–)   Step #2: 1 space away

What ions do atoms form?

Cl 1– Cl –or Chlorine gains an electron to become anion with a 1- charge

Example: In an ionic bond, what ion would O form?

  Step #1: metal or nonmetal?

What ions do atoms form?

Metals

Example: In an ionic bond, what ion would O form?

  Step #1: metal or nonmetal?   nonmetal = anion (–)   gain electron

What ions do atoms form?

Example: In an ionic bond, what ion would O form?

  Step 2: how far away from the noble gases?

What ions do atoms form?

2 spaces away

Example: In an ionic bond, what ion would O form?

  Step #3: write out the symbol and charge   Step #1: anion (–)   Step #2: 2 spaces away

What ions do atoms form?

O 2–

Oxygen gains two electrons to become anion with a 2- charge

Example: In an ionic bond, what ion would Na form?

  Step #1: metal or nonmetal?

What ions do atoms form?

Metals

Example: In an ionic bond, what ion would Na form?

  Step #1: metal or nonmetal?   metal = cation (+)   lose electron

What ions do atoms form?

Example: In an ionic bond, what ion would Na form?

  Step 2: how far away from the noble gases?

What ions do atoms form?

only 1 space away

Example: In an ionic bond, what ion would Na form?

  Step #3: write out the symbol and charge   Step #1: cation (+)   Step #2: 1 space away

What ions do atoms form?

Na 1+ Na +or Sodium loses an electron to become cation with a 1+ charge

Example: In an ionic bond, what ion would Mg form?

  Step #1: metal or nonmetal?

What ions do atoms form?

Metals

Example: In an ionic bond, what ion would Mg form?

  Step #1: metal or nonmetal?   metal = cation (+)   lose electron

What ions do atoms form?

Example: In an ionic bond, what ion would Mg form?

  Step 2: how far away from the noble gases?

What ions do atoms form?

2 spaces away

Example: In an ionic bond, what ion would Na form?

  Step #3: write out the symbol and charge   Step #1: cation (+)   Step #2: 2 space away

What ions do atoms form?

Mg 2+

Magnesium loses two electrons to become cation with a 2+ charge

Why do atoms form ions?   Atoms form ions to get 8 valence electrons

  Opposites attract ionic bond

Practice Questions   Practice questions worksheet

Homework   Study for quiz!

  Take home notes and practice questions from the past two weeks.

  Look at exit slips online (lpschem.wordpress.com)