Periodicity Flashcards
What is the outer shell called?
Valence shell
What is ionisation energy?
Energy required to release an electron and become an ion
What is the octet rule?
Atoms desire to form a stable octet (noble gas)
Why is the periodic table useful?
Properties and trends of elements are the basis of the periodic table’s design so allows accurate predictions of properties and reactions of a wide variety of substances
What are the chemical properties of metals?
Tend to lose e- and form positive ions
What are the physical properties of metals?
- Lustrous
- Malleable
- Good conductors of heat
- Good conductors of electricity
What are the chemical properties of nonmetals?
Tend to gain e- and form negative ions
What are the physical properties of nonmetals?
- Non-lustrous
- Brittle
- Poor conductors of heat
- Poor conductors of electricity
What properties do metalloids have?
Properties that are intermediate between metals and nonmetals
What happens when metals react with nonmetals?
E- are usually transferred from the metal to the nonmetal
Where are metals found on the periodic table?
The left of the metalloids
Where are nonmetals found on the periodic table?
The right of the metalloids
What is the screening factor?
The number of inner core electrons
How do you calculate the effective nuclear charge?
Number of protons - screening factor
what does Zeff stand for?
Effective nuclear charge
What is the trend of effective nuclear charge on the periodic table?
Increases across the periodic table
Why does effective nuclear charge increase as you move across to the right of the periodic table?
Additional valence electrons counterbalance the nuclear charge
What is the trend of atomic volume on the periodic table?
- Radii of atoms increases down a group
- Quantum (electron) number increases and are further away from nucleus
- Radii decreases from left to right
- Zeff is increased each time an electron is added, as a proton is added to the nucleus as well
What are the trends in ionisation energy?
- Smaller atoms have higher ionisation energies
- Decreasing the distance of the electron from the nucleus or increasing Zeff, increases IE
- The lower the IE, the easier to lose an electron to become a positive ion
Which one has lower ionisation energies: metals or nonmetals?
Metals
What is electron affinity?
Energy liberated when an element (in gas phase) gains an electron, becoming a negative ion
Which one has higher electron affinities: metals or nonmetals?
Nonmetals
Why are ionisation energy and electron affinity important?
Elements with low ionisation potential can easily give their electrons to elements with high electron affinities, forming an ionic bond and a complete valence shell
