Sept 7 Lecture (Intro) Flashcards
atoms are made up of:
neutrons
protons
electrons
the nucleus of an atom consists of
protons (+)
neutrons (charge 0)
define an element
substance composed of atoms with the same number of protons
define isotope
number of neutrons for any element may not be the same; variable # of neutrons possible
- some isotopes have more neutrons= heavier (eg C-14)
- some have fewer neutrons= lighter (eg C-12)
atomic mass number=
or protons + neutrons in nucleus
what are the 2 types of isotopes?
- stable isotopes
2. unstable (radioactive) isotopes
stable isotopes are used for:
fingerprinting, tracking pollutants, determining past temps, etc
unstable/ radioacitve isotopes are using in:
dating rocks, tracking enviro/ med processes, nuclear waste
- medical isotope= tC-99
an ion is:
an atom that is + charged or - charged (atoms can gain or lose e-)
define anion vs cation
anion= has gained e- (more e- relative to p+) cation= has lost e- (fewer e- relative to p+)
define compound
mixtures of 2 or more chemical elements in fixed proportions that have distinctive physical properties
- elements will bond b/c of electrical attraction, forming ionic bonds
OR
- the atoms may share e-, forming covalent bonds
cosmic/ solar abundances=
concentration of elements in our solar system in proportion to hydrogen
define minerals
naturally occurring, inorganic, solid elements or compound w/ a definite chemical composition and a regular internal crystal structure
*does not include anything man-made
minerals can form in 3 ways:
- Crystalization from a magma= as the magma cools, minerals begin to form
- crystal growth in the solid state= minerals can change after initial nucleation
- precipitation from solution= when a state of supersaturation is reached
the structure of a mineral is determined by:
*there are ___ways to arrange things in an open space according to math
how the anions are arranged and how the cations fit b/w them (diff sizes)
*216
define polymorphs and give ex
minerals w/ the same chemical composition, but diff structure
eg graphite vs diamond
explain the silicate group of minerals
variety of compounds based on silicon and oxygen
- quartz= glass manufacturing, clays for drilling mud etc
structures: tetrahedra, single & double chains, sheet, framework
asbestos
a crystal structure (silicate group) with useful properties: woven into fire resistant cloth- BUT lung cancer if breath in the fibres
mineral composition: list the nonsilicates
- carbonates (CO3): useful for building materials/ manufacturing
- sulfates (SO4)- useful for building materials
- sulfides- host for many metallic ores
- oxides - any metal combined with oxygen (iron & aluminum ores)
- native elements : minerals composed of single element (eg carbon as diamond and graphite, copper, gold, silver, platinum)
___ in groundwater in edmonton cause basement foundation cracks!
sulfates
define rocks
a cohesive aggregate of one or more minerals, which are held firmly together in a solid mass
list the 3 types of rocks
- igneous
- sedimentary
- metamorphic
define igneous rock
= melting of rocks in hot, deep crust and upper mantle
- formed by crystallization (solidification of magma)
- can occur slowly (beneath surface)= plutonic/ intrusive rock
- can occur quickly (comes to surface)= lava –> volcanic or extrusive
define sedimentary rock
weathering and erosion of rocks exposed at surface
- deposition, burial, lithification
- composed of compacted/ cemented grains which have become lithified