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COUNTING ATOMS. A. C. B. Vocabulary:. A. CHEMICAL FORMULA is the elements that make-up a compound or molecule. Chemical Formula. A. C. B. Vocabulary:. SUBSCRIPTS determines the number of ATOMS; small number. IF THERE ISN’T A NUMBER, ASSUME THERE IS ONLY ONE ATOM OF THAT ELEMENT!.
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A. C.. B. Vocabulary: A. CHEMICAL FORMULA is the elements that make-up a compound or molecule Chemical Formula
A. C. B. Vocabulary: • SUBSCRIPTSdetermines the number of ATOMS; small number IF THERE ISN’T A NUMBER, ASSUME THERE IS ONLY ONE ATOM OF THAT ELEMENT! Subscript
A. C. B. Vocabulary: Coefficient • COEFFICIENTSapply to the entire compound. It tells you the number of MOLECULES
H O The diagram to the left represents TWO molecules of water. H H O H
Steps to counting atoms: • Count the number of capital letters in the chemical formula • Line up the elements • Put the number of atoms beside the element • No number means it is ONE atom of that element 4. IF there are parenthesis, the subscript outside the parenthesis are multiplied by what’s inside. 5. Multiply the coefficient by the subscript for each element • No number means it is ONE molecule 6. Add same elements together when it is needed
LET’S PRACTICE! 2NaOH
Multiply by subscript (remember no subscript = 1) Na X 1 O X 1 H X 1
Multiply by Coefficient Na x 1 x 2 = 2 atoms of Na O x 1 x 2 = 2 atoms of O H x 1 x 2 = 2 atoms of H Total Number of Atoms is 6
PRACTICE 3C6H12O6 Remember the rules: Count caps Line up Elements Multiply by subscript Multiply by coefficient
Parenthesis Example 4H2SO4(OH)2 Count Caps. Line up Elements Multiply by subscript (if there is a parenthesis, the subscript outside the parenthesis are multiplied by what is inside) Multiply by coefficient