Chapter 2: The Periodic Table Flashcards
List 10 features of alkali metals.
- group 1 (first column of the periodic table)
- densities are lower than most other metals
- 1 valence electron
- low Zeff
- largest atomic radii within each period
- low ionization energies
- low electron affinities
- low electronegativities
- form univalent cations
- react readily with nonmetals (especially halogens)
List 3 features of alkaline earth metals.
- group 2 (second column of the periodic table)
- 2 valence electrons
- form divalent cations
What are the active metals?
the alkali metals and alkaline earth metals (groups 1 and 2)
so reactive that they are not naturally found in their neutral state
List 6 features of the chalcogens?
- group VIA or 16
- nonmetals and metalloids
- crucial for normal biological functions
- slightly less reactive than halogens
- 6 valence electrons
- small atomic radii and large ionic radii (due to proximity to metalloids)
- at high concentrations, many of these elements can be toxic/damaging
List 3 biologically important chalcogens and describe their importance.
- oxygen
- primary constituent of water, carbohydrates, other biomolecules
- sulfur
- an important component of certain amino acids and vitamins
- selenium
- important nutrient for microorganisms
- has a role in protection from oxidative stress
What are the physical properties of the halogens?
their physical properties are variable
they range from gases to liquid to solid forms
Discuss the chemical reactivity of the halogens. (4)
- very high electronegativities
- high electron affinities
- especially reactive towards alkali and alkaline metals
- note naturally found in their neutral state, but rather as ions (halides) or diatomic molecules
atomic size/radius trend on period table
effective nuclear charge
ionization energy trend
activation energy trend
electronegativity
definition and trend
a measure of the attractice force an atom exerts on an electron in a chemical bond
atomic radii