Chem 5AB Quiz Flashcards
Lavosier
Published a list of 30 substances that he called elements
Some of his elements were actually compounds
Dobereiner
Triads: Groups of 3 elements that shared similar properties
Some became tetrads and pentads
Periodicity- Patterns between elements
Law of octaves (Newlands)
Connection with atomic mass and chemical properties
Mendeleev
Elements arranged by atomic masses
Knew elements not yet discovered
Transition metals
Periodic law
Newlands
Organized atoms by atomic mass
Used musical and math background
7 columns
Law of octaves (no one accepted idea)
Modern periodic law (Henry Moseley)
The square root of the frequency of the x-ray emitted by an atom is proportional to its atomic number
Artificial elements
Transuranium elements
Neptunium Plutonium
Products of artificial processes
Periodic table is divided into
Groups (columns) and periods rows
Left and middle of the table
Metals
Right side of the table
Nonmetals
Metalloids
Share properties of both metals and nonmetals
The lanthanide series and actinide series are put
At the bottom of the table
Atomic radius
Measured using x-ray diffraction
Determined by electron cloud
More protons
More attraction
More attraction
Closer to nucleus
More protons
Smaller radii
Why the trend of atomic radius
Going down a group of family add extra layer of electrons for each level
Left to right- more protons means more attraction for electrons. Results in the shrinking of atomic radius
Ionic radius
Cations are smaller than their parent atoms (got rid of an electron)
Anions are larger than their neutral atoms (picked up electron)
Ionization energy
The energy needed to remove an electron from an atom
Dalton
Documented 60 element
Complex symbol system
Groups
Same # of valence electrons
Periods
Rows- same # of electron orbitals/sublevels
Periodic law (Mendeleev)
Properties of elements vary with their atomic number in a periodic way (there is a pattern)
When elements are arranged according to increasing atomic mass there is a repetition in their properties
