Exam 1 - Chapter 2 Flashcards
atoms
building blocks of life
matter
anything that takes up space
element
substance composed of only one type of atom, cannot be broken down
molecule
unit composed of two or more atoms joined by covalant bonds
compound
unit composed of two or more elements that are joined by chemical bonds
mixture
combination of 2 or more substances that do not chemically bond
protons
positive charge in nucleus 1da/amu
neutrons
neutral charge in nucleus 1da/amu
electron
negative charge in orbitals negligible
elements
atoms with same number of protons, OCHN=oxygen, carbon, hydrogen, nitrogen
atomic number
number of protons
mass number
sum of protons and neutrons
atomic mass
weight mass of atoms of an element in daltons
isotopes
atoms of an element that differ in number of neutrons
radioisotopes
unstable nucleus decays spontaneously giving off particles and energy to return to stability
radioactive decay
process of a radioisotope losing particles and energy over time
electron orbitals
- house electrons
- filled from lower to higher energy
- farther an electron is from the nucleus, the greater its potential energy
electron shells
1st - 2 electrons, each shell after = 8 electrons
free radicals
uncharged solitary atoms with unpaired electrons
ions
atoms with an unequal number of protons and electrons
chemical bond
attractive force that arises between two atoms when their valence electrons interact
ionic bonds
donation or theft of electrons results in ions, ions of opposite charge are strongly attracted to each other
electromagnetically
measure of the ability of an atom to pull electrons away from other atoms
polarity
separation of charge into partial positive and partial negative regions
covalent bonds
atoms share a pair of electrons
polar covalent
unequal sharing of valence electrons
non-polar
equal sharing of valence electrons
hydrogen bonds
partially positive hydrogen atom covalently bonded to one electronegative atom is attractive to another electronegative atom
van der waals interactions
asymmetrically distributed electrons in molecules or atoms result in hot spots of positive or negative charge
strength of bonds
covalent, iconic, hydrogen, van der waals
H
H=C=H
H
non polar
h-o-h
polar
na1e -> Cl7e = Na Cl8e
ionic
water —— water
hydrogen
chemical reactions
O2 + 2H2 (reactants) =(reaction) 2H20 (product)
