Chapter 3 Flashcards
Define chemical Stoichiometry
Area of study where the quantities if materials consumed and produced in chemical reactions are considered
If you know the __ __ of objects, the objects behave as they were all __
Average mass; Identical
To count atoms, determine the # of __ in a sample by finding its __
Atoms; Mass
Modern system of atomic masses is based in __ as the standard
12C
__ is assigned a mass of exactly __ atomic mass units (amu)
12C; 12
Define mass spectrometer
An instrument used to determine the relative masses of atoms or the isotopic composition of a natural element by the deflection of their ions on a magnetic field
Accelerating ions produce own __ __, interacts with applied __ __, which tends to change the path of the __ (most massive __ are deflected the __ & separate)
Magnetic field; Magnetic field; Ion; Ions; Least
Masses of atoms are called __ __; atomic mass of _ is an average value of isotopes
Atomic weight; C
Define mole
Number equal to the number of carbon atoms in exactly 12 grams of pure 12C
Define average atomic mass
Average mass of an element
Define molar mass (molecular weight)
Mass in grams of one mole of the compound
Define Avogadro’a number
6.022 • 10^23; number of units of a substance in one mole of it
Mass of 1 mole of an element is equal to its __ __ in __; 6.022 • 10^23 __ = 1 _
Atomic mass; Grams; Amu; g
To find the molar mass, sum the masses of the __ __
Component atoms
2 common ways to describe the composition of atoms
of atomsPercentage of elements
Define mass percent (weight percent)
Percent by mass of a given element in a compound ((mass of element in 1 mole of compound / total mass of 1 mole of compound) x 100)