Chem 😀 Flashcards
Atomic mass
Atomic number
Mass number
The mean of isotopic masses weighed for their natural abundance
Number of protons
The mass of both protons and neutrons
Name the 3 subatomic partials of the atom and then define its relative mass charge and location and significance
Proton 1 dalton + nucleus element mass
Neutron 1 Dalton 0 nucleus isotope mass
Electron .0005 daltons orbital \ electron cloud charge and chemical activities and bonding behavior
Element
Atom
Compound
Is a pure substance that cannot be broken down by chemical means
Smallest unit of matter that maintains its elemental properties
A compound is a group of elements that have been bound together
Properties of radio active isotopes
Same chemical behavior and reactivity as non radioactive elements
Emissions are detectable even at low levels
Each element has a decay rate that is constant and highly predictable
3 types of radioactive partials
Alpha particles
2 protons and 2 neutron (helium nucleus ) effect z -2 a-4
Skin deep clothing
Beta particles high energy electron z + 1 a = subcutaneous skin deep plexiglass
Gamma particles high energy photon no effect on nucleus internal tissue lead plates
Radioactive tracing ( act like normal element in the body but detectable )
Food sterilization
Cancer treatment
Radioactive dating
Application of radioactive elements
Half life
Time for 1/2 of the radioactive atom to decay
It is exponential
10^-6 10^10
Exponential decay formula
N =Noe^-(.693t/t half)
Electro static attraction
Attraction of two compounds or ions
(Weak) ionic bounds
Associated with ions
Electrostatic attraction between oppositely charged ions
Full permanent changes
Strong dry weak in water
Hydrogen bound (dipole dipole interaction )
Associated with polar molecules or polar regions of large molecules
Electrostatic attraction between opposite partial charges
Requires a polar covenant bond (o h) (o n)
Identified as hydrogen doner and accepter
Occurs between polar bond regions of molecules
Weak bond (10-30 kJ/mol)
Vanderwaals interactions induced dpole - induce dpole
Nonpolar molecules or nonpolar regions
Electrostatic attraction between induced dipoles
Two atoms must be pushed very close to each other
When close electrons synchronize this keeeps the elements from crashing in the middle
Very weak bonds 3-4 kJ/mol
Relevance of weak bonds in biology
Forms weak bonds releases energy
Breaking bounds requires energy
