Chapter 3: Periodicity Flashcards
(25 cards)
What does the Period number of the periodic table represent?
the number of occupied electron principle energy levels.
What is Periodicity?
How properties in elements repeat periodically.
Does shielding change across a period?
No
of protons - 10 = ?
Valence Electrons across periods
How is atomic radius measured?
1/2 the distance between neighboring nuclei. Also the distance from the nucleus to the outermost electrons of a bohr atom.
Attraction between the nucleus and electrons will increase across a period causing what to shrink?
Atomic Radius
What is the size of a positive ion relative to it’s parent atom?
Smaller than parent atom.
What is the size of a negative ion relative to it’s parent atom?
Larger than parent atom because of the increased electron repulsion between electrons in the outer principle energy level causes electrons to move further apart to increasing radius of outer shell.
How does ionic radius travel across the period?
It decreases across the period
How does ionic radius travel down the group?
It increases down the group
What are the 1st Ionization Energies?
the measure of attraction between the nucleus and the outer electrons.
How does 1st Ionization Energies travel across the period?
Increases across the period because an increase in nuclear charge causes an increase in attraction between outer electrons and nucleus making the electrons harder to remove.
How does 1st Ionization Energies travel down the group?
Decreases down the group.
What is the 1st electron Affinity in an element?
Is the energy change when 1 mole of electrons is added to 1 mole of gaseous atoms to form one mole of gaseous ions. Not available for noble gases. Exothermic
What is the formula for the 1st electron Affinity in an element?
X(g) + e^− → X^-(g)
What is the 2nd electron Affinity in an element?
it is endothermic because it is repelled by negatively charges X^- ion ( energy need to available for this to occur.
What is the formula for the 2nd electron Affinity in an element?
X^−(g) + e^− → X^2−(g)
What is a ground state?
Not an ion of the element.
Where are all the transition elements found?
In the d-block
What is a complex ion?
Complex ions are ions that are the big ones on the formula ( not real definition)
What is Electronegativity?
is defined as the attraction of an atom for a bonding pair of electrons
Endothermic
absorbs heat
Exothermic
gives out heat
How does Electron Affinities travel down the group?
It decreases
