LT#4: Periodic Trends Flashcards
The Periodic Law States that…
Chemical and physical properties of the elements repeat in a regular pattern when arranged by atomic number on the periodic table.
Define Effective Nuclear Charge (Zeff)
How strongly the valence electrons are attracted to the nucleus
Define Electron Repulsion (ER)
Repulsive force between electron shells due to them being negatively charged.
The more electron shells in between the nucleus and the valence electrons, the less attracted they are to the atom.
Proton Attraction (PA)
Opposite charge attraction between protons and electrons.
The more protons an atom has pulling on the same number of electron shells, the more attracted the valence electrons are to the atom.
Define Ionization Energy (IE)
The amount of energy required to remove an electron from an atom
Define Electronegativity (EN)
An atom’s ability to attract a pair of electrons in a chemical bond
Define Electron Affinity (EA)
The amount of energy released or absorbed when an atom gains an electron
Define Atomic Radius
The distance from the centre of the atom to its boundary within which the electrons travel
EN increases…
up (less ER) and right (more PA)
Radius increases…
down (more ER) and left (less PA)
EA increases…
up (less ER) and right (more PA)
IE increases…
up (less ER) and right (more PA)
Which is larger, P or Cl?
Why?
P
Less PA than Cl, so electrons able to spread out more.
Which has a higher EN, K or Rb?
Why?
K
Less ER than Rb, so nucleus is able to attract electrons stronger
Which has a higher first IE, Na, Li or Be?
Why?
Be
Less ER than Na and more PA than Li
