Exam One Flashcards
(37 cards)
Elemental composition of human body
HOCN - Hydrogen 63% Oxygen 24% Carbon 10% Nitrogen 1%
Chemical reactions
the union or separation of atoms (ie: breathing in O2, oxygen combines with carbon and is expelled as carbon dioxide so oxygen is bound with carbon)
Molecule
2 or more atoms combined (bound)
Atom
an element in its smallest form
Dalton’s Theory
all matter is composed of atoms that can neither be created nor destroyed
Ie: throwing a log on a fire turns it into carbon, hydrogen & cellulose in the gaseous form, it doesn’t get destroyed it just converts to another form
Neutron
No charge
Proton
Postitive Charge +
Electron
Negative charge -
Atomic number Z
the number of protons in an atomic nucleus. No two elements can have the same number of protons because they are different elements.
Electrically neutral
an atom (element) is electrically neutral when: Number of electrons (e-) = number of protons (p+) This atom will have no charge and is neutral
isotopes
same atomic number, but different atomic masses (so they have a different number of neutrons)
Inert gases or noble gases
Helium (He) Argon (Ar) Krypton (Kr) Xenon (Xe) Radon (Rn)
Properties: highly enert elements, do not react. All are gases at normal temp.
Alkali or light metals
Lithium (Li) Sodium (Na) Potassium (K) Rubidium (Rb) Cesium (Cs) Frandium (Fr)
Properties: In pure form they have a shiny luster, good conductors of heat/electricity
Halogens
Fluorine (F)
Chlorine (Cl)
Bromine (Br)
Iodine (I)
Properties: Nonmetals, poor conductors of heat/electricity, all react with hydrogen to form hydrogen halide (ie: hydrogen fluoride, hydrogen chloride – acid, etc)
Transition Metals
Magnesium (Mg) Sulfur (S) Aluminum (Al) Phosphorus (P) Silicon (Si)
Properties: variable changes, Mg and S have a decrease in metallic properties. Mg and Al are metals, P and S are nonmetals. Si is an intermediate
Electronegativity
the ability of an atom to draw (attract) electrons towards it.
Ionization energy
the energy required to ionize an element
Gamma Radiation Levels
a – least energetic, most safe
B – more energetic, permeates more
Y (gamma) – most energetic, most dangerous because it permeates right through you.
Cation
positively charged atom or molecule
Anion
negatively charged atom or molecule
Covalent bonds
chemical bond that results from sharing valence electrons
dipole
a molecule with one end having a slightly (or partial) negative charge and the other end having a slight positive charge (not ionic bonds).
Paramagnetic
02 is paramagnetic (attracted into magnetic field) due to unpaired electrons
Van der Waals Forces
attractive forces between atoms and molecules that are not formal bonds. These forces affect (among other properties)
1) boiling and melting points,
2) vapor pressures (ie, volatilities),
3) solubilities in different media,
4) drug interaction with receptors.