Right Now Copy down your homework Get ready to answer today’s Do Now

Do Now: What do the following things have in common Do Now: What do the following things have in common? What is the benefit to using them? BRB ROTFL SMH LOL GR8 UR XOXO JK

Chemical Symbols and Formulas Add the new notes to your table of contents, and then turn to the next clean page and set up your title and date

Symbols – represent an element Elements are represented using a 1 or 2 letter symbol The first letter MUST be capitalized, and the second must be lowercase Example: H = hydrogen, He = helium

Parts of an Element Box on the Periodic Table Tape In

Formulas – represent a molecule Made up of symbols and subscripts Symbols abbreviations that represent elements, they tell you what element(s) are in the molecule Subscripts numbers found below and to the right of each symbol, they tell you how many of each element make up the molecule (no subscript = only one atom of that element) Ex: H2O subscript

Periodic Table of Elements Tape this in just like the Matter Decision Chart from yesterday Add Periodic Table of Elements to your Index

Practice Counting Atoms in a Chemical Formula C = Carbon – ___ H = Hydrogen – ___ AgNO3 Ag = Silver – ___ N = Nitrogen – ___ O = Oxygen - ___

more practice…

Tape in Tonight’s HW

Honors A polyatomic ion is a group of two or more atoms bonded together that then bond to another atom/group as a unit. (add to index) If there are more than one of these units bonded in a compound they are contained within parentheses and a subscript is used. The subscript is distributed to all of the elements in the polyatomic ion. Ex: Ca(NO3)2 Ag(S2NO4)3 Ca = 1 -Ag= N = 1 x 2 = 2 -S= O = 3 x 2 = 6 -N= -O=

How many Carbon atoms are there in the following formula C6H12O6 Exit Pass How many Carbon atoms are there in the following formula C6H12O6 6 1 12