Lesson 14: Periodic Trends

Lesson 14: Periodic Trends

Review: Cations and Anions negative positive electrons n anion cation Metals lose electrons when they undergo chemical reactions. Na will always lose one electron. Nonmetals gain electrons when they undergo chemical reactions. Cl will always gain one electron.

Review: Cations and Anions Noble gases

Electron Configurations There is not a section in your notes for this - you may take extra notes if you d like. Otherwise, just pay attention!

Electron Configurations He A neutral atom of He has two electrons in its outer shell, making it stable.

Electron Configurations He A neutral atom of He has two electrons in its outer shell, making it stable. Ne A neutral atom of Ne has eight electrons in its outer shell = stable

Electron Configurations He A neutral atom of He has two electrons in its outer shell, making it stable. Ne A neutral atom of Ne has eight electrons in its outer shell = stable Ga A neutral atom of Ga has three electrons in its outer shell, making it unstable and reactive.

Metals lose electrons to become stable like the Noble Gases.

Metals lose electrons to become stable like the Noble Gases. He protons neutrons electrons

Metals lose electrons to become stable like the Noble Gases. He How can Li have the same electron configuration as He? Li + protons neutrons electrons Li will lose its one valence electron. Has 3 protons and 2 electrons, so is positively charged (+1)

Metals lose electrons to become stable like the Noble Gases. Ne protons neutrons electrons

Metals lose electrons to become stable like the Noble Gases. How can Na have the same electron configuration as Ne? Ne protons neutrons electrons Na + Na will lose its one valence electron. Has 11 protons and 10 electrons, so is positively charged (+1)

Metals lose electrons to become stable like the Noble Gases. How can Mg have the same electron configuration as Ne? Ne Mg 2+ Mg protons neutrons electrons Mg will lose its two valence electrons. Has 12 protons and 10 electrons, so is positively charged (+2)

Nonmetals gain electrons to become stable like the Noble Gases.

Nonmetals gain electrons to become stable like the Noble Gases. How can F have the same electron configuration as Ne? Ne F F - protons neutrons electrons F will gain one electron into its valence shell. Has 9 protons and 10 electrons, so is negatively charged (-1)

Nonmetals gain electrons to become stable like the Noble Gases. How can O have the same electron configuration as Ne? Ne O 2- O protons neutrons electrons F will gain one electron into its valence shell. Has 9 protons and 10 electrons, so is negatively charged (-1)

Review: Cations and Anions Noble gases The number and distribution of electrons around an atom.

answer all questions below Practice on page 4. Think about: their sizes, charges, amount of energy each has, relative location, role in chemical reactions and

When atoms gain or lose electrons, valence electrons are always involved!

When atoms gain or lose electrons, valence electrons are always involved! Atoms lose their valence electrons. Ga 3+

When atoms gain or lose electrons, valence electrons are always involved! Atoms lose their valence electrons. Atoms gain electrons that will be added to their valence shell. Empty spot for another electron Ga 3+ Se Empty spot for another electron

When atoms gain or lose electrons, valence electrons are always involved! Atoms lose their valence electrons. Atoms gain electrons that will be added to their valence shell. Ga 3+ Se 2-

Remember the trend: lose gain Metals electrons while nonmetals electrons

All alkali metals (Group ) will electron to form ions. 1+ 1A lose one All alkaline earth metals (Group ) will electrons to form ions. 2+ 2A lose two B, Al, Ga lose three Group 3A, containing, will electrons to form ions. 3+

C, Si, Ge 4 Group 4A, containing, can either gain or lose electrons to form 4+ or 4- ions. N, P, As gain three Group 5A, containing, will electrons to form 3- ions. Group 6A, containing, will electrons to form ions. 2- O, S, Se, Te gain two 7A gain one 1- All halogens (Group ) will electron to form ions. 8A not form any ions; are not reactive All noble gases (Group ) will.

Charge that each atom in column will take: 1+ Metals Lose electrons & form cations Nonmetals gain electrons & form anions 4+ 2+ 3+ 3-2- 1-4-

Complete Now:

CHECK YOUR WORK: Ba 2+ P 3- Br - Ca 2+ Cs + Al 3+ O 2- N 3- none Be 2+ As 3- B 3+ Na + Ga 3+ none I - C 4+ S 2- F - C 4-

Draw the staircase to help you remember metalloids