When elements are arranged in order of increasing atomic numbers, elements with similar properties occur at periodic (regular) intervals.
Who proposed Periodic Law?
Dmitri Ivanovich Mendeleev and Julius Lothar Meyer in 1869
effective nuclear charge, Z(eef)
the net nuclear charge that an electron feels from attractions to the protons in the nucleus and repulsions from all the other electrons
Within a particular shell, electrons in subshells with lower values of l "shield" electrons with (higher/lower) values of l more effectively.
Electrons with higher values of l feel (more/less) attraction for the nucleus than do electrons with lower values of l because they are more "shielded" from the nucleus.
The more effective the other __________ are at repelling an outer _______, the more shielded we say the ________ is from the nucleus.
In many electron atom, an electron in a ___ orbital is higher in energy than an electron in a 2s orbital.
The order of filling orbitals r______ the extent of the shielding effect of electrons in many electron atoms.
1/2 the distance between the nuclei of adjacent like atoms in a compound
We find experimentally that the atomic radius of the elements tend to do what as we move down the periodic table.
increase in size
We find experimentally that the atomic radius of the elements tend to do what as we move to the right across the periodic table?
A shell contains
all the orbitals of an atom that have the same n quantum number
Electron shells are (exact,diffuse) regions of higher electron density.
The electron density for electrons with a larger principal quantum number is found (closer,farther)from the nucleus of the atom.
the distance of a shell from the nucleus is explained by the _____ ___ ______.
effective nuclear charge