ACU: General Chemistry 1 Exam #2

amount of a specified pure product actually obtained from a reaction

solution in which solvent is water

• amount of solute
• volume or mass of solution or solvent

• moles of solute
• L of solution

• mass of solute X100%
• mass of solution

• actual yield X100%
• theoretical yield

qualitative relationship among substances as they participate in chemical reactions

• dispersed medium
• dispersing medium
• homogenous mixture of 2 or more substances

• no detectable change in the quantity of matter during a ordinary chemical reaction
• no loss or gain of matter

V₁M₁ = V₂M₂

the spectrum associated w/ absorbtion of electromagnetic radiation by atoms resulting from transitions from lower to higher electronic energy states

• Family: 1A
• Family: 2A
• Family: 7A
• Family: 8A

helium ion w/ a 2+ charge; an assembly of 2 protons and 2 neutrons

• angular momentum quantum number
• designates subshell or set of orbitals w/in a given main shell
• l = n-1
• ex. n=7; l=0,1,2,3,4,5,6

positive electrode in cathode ray tube

arbitrary mass unit that is 1/12 the mass of the carbon-12 isotope

weighted average of the masses of the constituent isotopes of an element; the relative mass of atoms of different elements

number of protons in the nucleus

region or volume in space in which the probability of finding electrons is the highest

guide for predicting the order in which electrons fill subshells and shells in atoms

relates wavelengths in the hydrogen emission spectrum to simple intergers

a stream of positively charged paricles (cations) that moves toward the negative electrode in a cathode ray tube; observed to pass through canals (holes) in the negative electrode

negative electrod in the cathode ray tube

beam of electrons going from the negative electrode toward the postive electrode in a cathode-ray tube

a closed glass tube containing a gas under a low pressure w/ electrodes near the ends and a luminescent screen at the end near the positive electrode produces cathode rays when high voltage is applied

the variation in properties of elements w/ their positions in the periodic table

a spectrum that contains all wave-lengths in a specified region of the electromagnetic spectrum; rainbow

• begins in the 3rd shell
• 5 orbitals per shell
• 10 electrons total
• higher energy than s and p in the same shell

2 or more orbitals that have the same energy

weak repulsion by a magnetic field; associated w/ all electrons in an atom, molecule, or substance being paired

energy that is propagated by means of electric and magnetic fields that oscillate in directions perpendicular to the direction of travel to the energy

• subatomic particle
• mass= .00054858
• charge= -1

the specific distribution of electrons in the atomic orbitals of atoms and ions

the transfer of an electron from one energy level to another

the spectrum associated w/ emission of electromagnetic radiation by atoms or by other species resulting from electron transitions from higher to lower energy states

any energy state other than the ground state of an atom, ion, or molecule

• beginning in the 4th shell
• 7 orbitals per shell
• 14 electrons total
• higher energy than s, p, and d orbitals in the same shell

• the property that allows a substance to become permanently magnetized when placed in a magnetic field
• exhibited by iron, cobalt, and nickle and some of their alloys

the numer of crests of a wave that pass a given point per unit time

• wubatomis particles of which all matter is composed
• protons, electrons, and neutrons are fundamental particles

the lowest energy state or most stable state of an atom, molecule, or ion

the elements in a vertical column of the periodic table

it is impossible to determine accurately bothe the momentum and position of an electron simultaneously

each orbital of a given ubshell is occupied by a single electron before pairing begins

• 2 or more forms of atoms of the same element w/ diggerent masses
• atoms containing the same # or protons but different #s of neutrons

an atomic emission or absorption spectrum

• quantum mechanical solution to a wave equation that designates the particular orbital w/in a given subshell (s,p,d,f) in which an electron resides.
• the p_x, p_y, and p_z orbitals have different magnetic quantum #s

the integral sum of the numbers of protons and neutrons in an atomm

an instrument that measures the charge-to-mass ratios of charged particles

• an element below and to the left of the stepwise division (metalloids) of the periodic table; about 80% of the known elements
• elements above and to the right of the metalloids in the periodic table
• elements w/ properties intermediate between metals and nonmetals: B, Si, Ge, As, Sb, Te, Po, and At.

spontaneous decomposition of an atom

• subatomic particle
• mass= 1.0087 amu
• charge= 0

the very small, very dense, positively charged center of an atom containing protons and neutrons, except for ^1₁H

the symbol for an atom,^a_zE, in which E in the symbol for an element, z is its atomic number and a is its mass number

each allowed wave description of a stable state for an electron in an atom; a region of space in which the probablility of finding an electron is high

beginning with the second shell, a set of three degenerate, mutually perpendicular, equal-arm, dumbbell-shaped atomic orbitals per shell

interaction of two electrons with opposite m_s values in the same orbital also known as spin pairing

attraction toward a magnetic field, stronger than diamagnetism, but still very weak compared w/ ferromagnetism; due to presence of unpaired electrons

no 2 electrons in the same atom may have identical sets of 4 quantum numbers

the elements in a horizontal row of the periodic table

the properties of hte elements are periodic functions of their atomic numbers

an arrangement of elements in order of increasing atomic number that also emphasizes periodicity

regular periodic variations of properties of elements w/ atomic number (and position in the periodic table)

emission of an electron from the surface of a metal, caused by impinging electromagnetic radiation of certain minimm energy; the resulting current increases with increasing intensity of radiation

a "packet" of light or electromagnetic radiation; also called a quantum of light

• principal quantum number
• designates the main shell, or energy level, in which an electron resides

• subatomic particle
• mass= 1.0073
• charge= +1

• a "packet of energy"
• proton

a mathematical method of treating particles ont he basis of quantum theory, which assumes that energy (of small particles) is not infinitely divisible

numbers that describe the energies of electrons in atoms; they are derived from quantum cechanical treatment

sperically symmetrical atomis orbital; one per shell

any of a number of lines corresponding to definite wavelegths in an atomic emission or absorption spectrum; these lines represent the energy difference between two energy levels

display of component wavelegths of electrommagnetic radiation

• spin quantum number
• indicates the relative spins of electrons ("spin up or spin down")

the distance between two identical points of a wave

his "oil-drop" experiment was used to determine the exact electrical charge on an electron and its exact mass

proposed that electrons behaved like "little packets of energy" which were called "photons" or "quanta". Einstein is also associated with the "photoelectric effect

his model of the atom had a very small nucleus at the center surrounded by several circular orbits in which the electrons were placed. his model was used to explain the spectrum of hydrogen and the rydberg equation

Uncertainty principle

exclusion principle- no 2 electrons in an atom may have identical sets of 4 quantum numbers

gold leaf experiment- led to a new model of the atom in which there is a small dense nucleus surrounded by a diffuse electron cloud

• plum pudding of raisin muffin model
• identified cathode rays as being electrons

hund's principle- orbitals of equal energy are half-filled w/ electrons before spin pairing occurs

father of the periodic table

concluded that very small particles such as electrons also display wave properties

noticed that a beam of positive particles were generated in vacuum tubes in addition to cathode rays. these poitive paritcles wer called "canal rays" and eventually identified as protons

in 1913, young englishman that determined that the atomic number of an atom was more fundamental to determining the properties of the elements than atomic weight. he enlisted in the british army and was killed at Gallipoli in 1915

• first to use cathode ray tubes
• determined that cathode rays are negatively charged and have mass

discovered the nucleus of the atom contains more than just protons (neutrons)