Block 1: Atomic Structure & Bonding Flashcards
(11 cards)
How do the Gaia & Medea hypothesis differ?
The Gaia hypothesis describes organisms & their environment as a single self-regulating system
The Medea hypothesis describes life as self-destructive
Describe each of Goldschmidt’s 6 element categories
Lithophile: bonds with oxygen to form silicates & oxides, concentrated in crust
Siderophile: associates with metallic iron, migrates to core
Chalcophile: bonds with sulphur to form sulphides, concentrated in mantle & crust
Atmophile: exists primarily as gas (volatile)
Organophile: bonds with organic matter, concentrated in the biosphere
Fluid-mobile: readily transported by aqueous fluids, concentrated in subduction zones
What does electronegativity measure?
The tendency of an atom to attract a bonding pair of electrons. This can predict bonding behaviour
How does electronegativity determine bond type?
Covalent bonds form between atoms with the same electronegativity, which share outer electrons
Ionic bonds form between atoms with different electronegativities, as one will take the other’s outer electrons
Van der Waals bonds form between molecules regardless of electronegativity when electron oscillation forms momentary attraction
What are the 3 definitions of acids & bases?
Lewis: acids accept electrons and bases donate electrons
Brønsted-Lowry: acids donate protons and bases accept protons
Arrhenius: Acids produce H+ in water and bases produce OH-
How does the pH scale rank acidity/alkalinity?
pH = -log[H+]
What are the steps for drawing a Lewis diagram?
- Determine the central atom (the least electronegative besides hydrogen)
- Arrange the outer atoms (H & halogens are always outer atoms)
- Count total valence electrons
- Draw bonds between central and outer atoms
- Fill octets around outer and central atoms
- Move non-bonding electrons between atoms to fulfil all octets while maintaining the appropriate total electron count
- Leave charged atoms with appropriate electron totals
What are the formulas & properties of hydrochloric, sulphuric, carbonic, and nitric acid?
When is Ka needed in acid base calculations?
HCl is a strong monoprotic acid
H2SO4 is diprotic with a strong 1st dissociation and a partial 2nd
H2CO3 is a weak diprotic acid
HNO3 is a strong monoprotic acid
Ka is required for weak acids, as they do not fully dissociate
What are the formulas and properties of bicarbonate, hydroxide, ammonia, and carbonate?
HCO3- is a weak base derived from H2CO3
OH- is a strong base
NH3 is a weak base that accepts a proton to become NH4+
CO32- is a weak base
What is the relationship between molar mass, atomic mass, & moles
Atomic mass is the mass (AMU) of 1 atom of an element, reflecting the weighted average of its natural isotopes, whereas molar mass (g/mol) is the mass of a mole of that element in grams. A mole is the amount of atoms required to form an element’s molar mass in grams
How does the periodic table display trends in valence electrons & electronegativity.
The 8 main (tall) columns of the periodic table represent elements with 1-8 valence electrons, with H having 1 & the noble gases 8
Electronegativity generally increases upwards & to the left of the table
