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Molecular Formulas. A molecule is a neutral group of atoms united by covalent bonds. A substance that is made of molecules is called a molecular substance . To describe the composition of a molecular compound , chemists often use a molecular
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A molecule is a neutral group of atoms united by covalent bonds. A substance that is made of molecules is called a molecular substance. To describe the composition of a molecular compound, chemists often use a molecular formula. A molecular formula tells you how many atoms are in a single molecule of the compound.
What is a subscript? If a molecule contains more than one atom of a particular element, this quantity is indicated using a subscript after the chemical symbol. NH3 Subscript
GLUCOSE EXAMPLE: The molecular formula for glucose (a simple type of sugar): C6H12O6 6 atoms of carbon 12 atoms of hydrogen 6 atoms of oxygen
SAMPLE PROBLEMS: 1. What elements are in the following compound: Lithium acetate (LiC2H3O2)? a. Lithium b. Carbon c. Hydrogen d. Oxygen
LiC2H3O2 2. How many atoms of each element are in the compound above? Li = 1 C = 2 H = 3 O = 2
3. How many total # of atoms are in the following compound: Ammonium phosphate ((NH4)3PO4)? N = 3 H = 12 P = 1 O = 4
4. Write the chemical formula for the following compound. 1 atom of gold and 3 atoms of chlorine AuCl3 Au Cl Cl Cl
Practice Problems Part A 5. 2 atoms of hydrogen, 1 atom of sulfur, and 4 atoms of oxygen H2SO4
Part B 1. ZnS Zinc Sulfur
Part C 1. Glucose: C6H12O6 Carbon = 6 Hydrogen = 12 Oxygen = 6
Number of Atoms in a Formula 18. Mg(C2H3O2)2 Mg = 1 C = 4 15 atoms H = 6 O = 4
Great Combinations • Phosphorus pentoxide O O P O P O O