edHelper.com
Earth Science
Earth Lab: Valence Electrons



Earth Lab: Valence Electrons
Reading Level
     edHelper's suggested reading level:   grades 9 to 10
     Flesch-Kincaid grade level:   9.53

Vocabulary
     challenging words:    unreactive, valance, valence, metallic, periodic, atom, calculate, element, outermost, electron, minus, stability, whose, characteristic, determine, within
     content words:    In Groups


Print Earth Lab: Valence Electrons
     Print Earth Lab: Valence Electrons  (font options, pick words for additional puzzles, and more)


Quickly Print
     Quickly print reading comprehension


Proofreading Activity
     Print a proofreading activity


Feedback on Earth Lab: Valence Electrons
     Leave your feedback on Earth Lab: Valence Electrons  (use this link if you found an error in the story)



Earth Lab: Valence Electrons
By Trista L. Pollard
  

1     Just when you thought electrons were electrons, along comes valence electrons. Valence electrons are the outermost electrons in an atom's electron cloud. These electrons determine the chemical properties of an element.
 
2     On the periodic table elements are organized according to their chemical properties and in groups. The atoms of each element within that group usually have the same number of valence electrons. The group number on the periodic table column helps to show the number of valence electrons in each element's atoms. Elements in groups 1 and 2 have one or two valance electrons. In other words, the number of valence electrons in an atom from these groups equals the atom's group number.
 
3     Groups 3 through 12 tend to have elements with two or more valence electrons. In Groups 13 through 18, there is a specific way to calculate valence electrons. Atoms in these groups have the same number of valence electrons as the atoms' group number minus 10. The only element that does not follow this rule is helium (He) which has only two valence electrons. Group 18 atoms have 8 valence electrons. So why is it important to know about valence electrons?

Paragraphs 4 to 5:
For the complete story with questions: click here for printable


Copyright © 2009 edHelper