Your cell phone should be away during all times today.

Learning Intentions

• You can determine how many atoms of each type of atom are in a formula

• You can determine the atomic weight/mass of each type of atom in the formulas and add up all the weights/masses to get formula mass for the substance.

• You can describe percent composition and calculate it.

• You can define a mole and used it to count particles.

• You can do calculations between mole, mass and number of particles of a substance.

Content Standards being covered:

*Student understands what the letters and numbers stand for in a compound formula, can use those letter and numbers to determine how many of each type of element there are in a formula.
101. A compound’s formula will describe which elements are present in the compound and how many atoms of each.
102. In a compound, the subscript after an element will describe the number of atoms of that element only
103. If a subscript is placed on the outside of a parentheses that contains more than one element, the subscript will apply to all of the atoms within the parentheses
104. A coefficient placed in front of a compound describes the total number of that entire compound present
107. The total mass of a compound is the sum of all of the atom’s masses that make up the compound

Journal Entry:

What is percent composition of NaMnO₄?