Unit 1: Atomic Structure & Property Flashcards
Homogenous mixture (solution)
The
composition of the mixture is the same
throughout (at the atomic/molecular level).
Heterogeneous mixture
The composition is
not uniform throughout.
compound (chemical means)
a substance composed of atoms
of two or more elements chemically united in fixed
proportions
extensive property
depends upon
how much matter is is being considered
intensive property
does not
depend upon how much matter is is being
considered
density=
m/V
Avogadro’s number (number of atoms in 12 g of carbon-12)
6.022 x 10(^23)
Sig Figs
-significant= not zero, sandwich zeros, right of decimal point
-not significant= left of first nonzero digit
-addition- smallest decimal
Isotopes
are atoms of the same element (same number of
protons) but different numbers of neutrons in their nuclei.
molecule
an aggregate of two or more atoms in a definite arrangement held together by covalent bonds.
ion
atom, or group of atoms, that has a net
positive or negative charge (cations lose, anions gain)
Dalton’s Laws
-Multiple proportions (ratio of compound)
-Conservation of Mass
molecular formula
exact number of
atoms of each element in a molecule of the
substance.
empirical formula
simplest
whole-number ratio of the atoms in a substance.
ionic compounds
combination of cations
and anions, formula is always the same as the empirical formula, sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero
Montamic anion names end in
ide (ex. nitride) (so ionic compound would be metal+nonmetal, barium chloride)
Transition metal ionic compounds
ex. iron (II) chloride
-ic, refer to a cation with a larger charge.
-ous, suffix indicates the cation with the lesser relative cation charge,
Molecular compounds
-Made of nonmetals or nonmetals +
metalloids
-element further left and bottom n periodic table is first.
-prefix mono, di, etc then last ends in “ide”
acid
-yields hydrogen ions (H+) when dissolved in water
-ex. HCl
-(oxoacid contained H, O, and another element)
base
-substance that yields
hydroxide ions (OH–) when dissolved in water
-ex. NaOH
Hydrates
-compounds that have a specific
number of water molecules attached to them.
-
Functional Group
in orgo chem, specific group of atoms or bonds within a compound that is responsible for the characteristic chemical reactions of that compoundd
For any element
atomic mass (amu) =
molar mass (grams)
Molecular mass
the sum of
the atomic masses (in amu) in a molecule
Formula mass
sum of the atomic masses
(in amu) in a formula unit of an ionic compound
Percent Composition and Empirical Formulas
assume 100g
%–>assume g–>mol (divide by smallest)
Limiting Reactants
- balance 2. grams given–> moles 3. moles of the desired product (based on _) using mole ratio 4. keep the smaller number
Electromagnetic
radiation
the emission
and transmission of energy
in the form of
electromagnetic waves
speed of light=
wavelength (lambda) times frequency
Energy(discrete units, quantum)=
h(plank’s constant) x v
1st Ionization energy
-the strength of the coulombic attraction of the outermost, easiest to remove, electron to the nucleus
-increases across period (as #protons increase in same energy level)
-decreases down group as e- in higher energy level (shielding)
ionization chart
Large jump in IE when removing less-shielded core electrons (2nd & subsequent IE’s increase as coulombic attraction of remaining e–’s to nucleus increases)
Aufbau principle
Fill up” electrons in lowest energy orbitals
Hund’s rule
The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins
orbitals
s (1), p (3), d (5), f (7)
Effective nuclear charge (Zeff)
the “positive charge” felt
by an electron
Is cation or anion smaller than atom form?
-Cation is always smaller than atom from which it is formed.
-Anion is always larger than atom from which it is formed.
Electron affinity
the negative of the energy change that occurs when an electron is accepted by an atom in the gaseous state to form an anion.
solution
homogenous mixture of 2 or more
substances
solute
substance(s) present in the
smaller amount(s)
solvent
substance present in the larger
amount
electrolyte
when dissolved in
water, results in a solution that can conduct electricity.
nonelectrolyte
substance that, when dissolved,
results in a solution that does not conduct electricity (free moving pathway for electrons)
Weak Electrolyte – not completely dissociated
–> over <—
Strong Electrolyte
100% dissociation
Always soluble- solubility rules
N (nitrates No3-)
A (acetates C2H3O2-)
G (group 1)
S (sulfates SO4-2)
A (ammonium NH4+)
G (group 17)
Exceptions
—(to sulfates and group 17)
P (lead Pb+2)
M (Mercury Hg2+2)
S (silver Ag+)
—(to sulfates)
Castro Bear
Ca+2
Sr+2
Ba+2
