Atomic Structure Flashcards
What were the five points to Dalton’s model of the atom?
- all matter composed of tiny indivisible particles called atoms
- atoms cannot be created or destroyed
- atoms of the same element are alike in every way
- atoms of different elements are different
- atoms can combine together in small numbers to form molecules
compound
substance made by chemically combining two or more elements
Describe the actual model of the atom
- made up of sub-atomic particles
- nucleus contains protons and neutrons
- electrons occupy space outside nucleus
Why is atomic number important?
defining property of element
mass number
number of protons and neutrons
atomic number
number of protons
isotope
atoms of same element with different numbers of neutrons
ion
atom which has gained or lost electrons
How do isotopes differ from original atom?
heavier isotopes diffuse more slowly
empirical formula
simplest whole-number ratio of elements in compound
hydrated salt
compounds that contain fixed ratio of water molecules
water of crystallization
water within crystalline structure of compound
molecular formula
shows all atoms present in a molecule
How do you calculate molecular formula?
X(mass of empirical formula) = molar mass