The Periodic Table Flashcards
How are the blocks in the periodic table described?
by their characteristic orbitals, which are determined by the highest energy electron(s)
Describe the s-block
first two groups which are the alkali metals and alkaline-earth metals, as their outermost electrons are in the s orbitals
Describe the p-block
last six groups, excluding helium, include all non-metals, the semi-metals, and post-transition metals; valence electrons are in p orbitals
Describe the d-block
transition metals group 3-12. outermost electrons are in one or more d-orbital electrons
Describe the f-block
inner transition elements, usually the lanthanoids and actinides series both of which are radioactive
What are the representative elements?
s-block and p-block
What are the anomalies in filling orbitals and why?
- when a transition metals loses an electron for a cation, the first two electrons are removed from the s ones, then the d
- electrons adopt the lowest energy state; which is the most stable
- a sublevel which is exactly half-filled is more stable than a partially filled sublevel
- this involves the promotion of an s electron to the next d shell to achieve a half or full d shell
What are the elements that have anomalies in filling orbitals?
chromium
copper
molybdenum
palladium
silver
gold
Define “isotope”
an atom which contains a different number of neutrons in its nucleus than some other atom of the same element
What does this mean for isotopes?
different isotopes means different masses
What is the standard atomic weight
- otherwise known as the relative atomic mass
- weighted average of the masses of its naturally occurring isotopes based on the carbon-12 isotope which is taken to be 12 amu
Why are some relative atomic masses whole numbers?
- all due to coincidence
- one isotope may dominate the composition with only tiny amounts of lighter or heavier isotopes
