Periodic Table Study Guide Determining Shells and Valence Electrons
Periods Each row is called a “period” The elements in each period have the same number of shells 1st Period = 1 Shell 2nd Period = 2 Shells 3rd Period = 3 Shells 4th Period = 4 Shells www.chem4kids.com
Groups Group 8 = 8 valence e- Group 1 = 1 valence e- Except for He, it has 2 electrons Group 2 = 2 valence e- Each column is called a “group” 3, 4, 5, 6, 7 Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons” www.chem4kids.com
Transition Metals Transition Metals have slightly different rules for shells and valence electrons. This is something you will learn about in High School Chemistry. www.chem4kids.com
Determine the number of shells and the number of valence electrons for: Carbon - C 2nd Period = 2 shells 4th Group = 4 valence electrons www.chem4kids.com
Determine the number of shells and the number of valence electrons for: Sodium - Na 3rd Period = 3 shells 1st Group = 1 valence electron www.chem4kids.com
Write your answers in your notebook. Ne Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Neon 10 10 p+; 10 n 10 e- 2 (period 2) 8 (group VIII)
Write your answers in your notebook. H Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Hydrogen 1 1p+; 0 n 1 e- 1 (period 1) 1 (group I)
Write your answers in your notebook. Be Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Beryllium 4 4p+; 5 n 4 e- 2 (period 2) 2 (group II)
Write your answers in your notebook. Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Sulfur 16 16p+; 16 n 16 e- 3 (period 3) 6 (group VI)
Write your answers in your notebook. Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Potassium 19 19 p+; 20 n 10 e- 4 (period 4) 1 (group I)
Write your answers in your notebook. He Name the element: Atomic number: Number of p+ and n in nucleus: Number of e- in electron cloud: Number of e- energy shells: Valence electrons: Helium 2 2 p+; 2n 2 e- 1 (period 1) 2 (group VIII)
Remember This About He: Helium is the exception in Group 8. Since it has just one shell, that shell can only fit 2 electrons instead of 8. It is in this group because all the elements have a full outer shell.