CHEM 1030 EX 1

ELECTRONS AND STUFF

matter

anything with mass that occupies space, particulate

structure of a substance

determines chemical and physical properties

atom

smallest representative part of an element

molecule

a group of atoms chemically bonded together

chemical bond

force that holds together two atoms in a molecule

element

a pure substance, made of the same types of atoms

compound

a pure substance, made of different types of atoms

chemical reaction

a process in which one or more substances are converted to one or more different substances by the breaking/forming of bonds

phase change

a physical change (like ice to water)

distillation

separates liquid mixtures

filtration

separates a solid from a liquid or gas

homogeneous

a mixture that is uniform throughout

heterogeneous

a mixture that is NOT uniform throughout

1kg x m²/s²

unit of energy (Joule)

precision

certainty to which a measurement is known, aligns with reproducibility and standard deviation

accuracy

agreement of a measured value to the true value

reproducibility

degree of agreement among several measurements of the same quantity

temperature

measure of kinetic energy

intensive property

INdependent of amount of substance (density, color, odor, malleability)

extensive property

Dependent on amount of substance (mass, volume, length)

hypothesis

tentative, testable/falsifiable explanation

experiment

tests the hypothesis; supports or disproves

theory (model)

set of tested hypotheses giving an overall explanation of some phenomenon (explains the “why”)

scientific law

generally applicable statement of a fundamental scientific principle thats tells us what will happen (not why)

1. each element is composed of tiny, indestructible particles called atoms

2. all atoms of a given element have the same mass and other properties that distinguish them from atoms of other elements

3. atoms combine in whole-number rations to form compounds

4. in a chemical reaction, only bonds between atoms change

Dalton’s Atomic Theory (4 parts)

Plum Pudding Model

based on discovery of low-mass e^- by J.J. Thomson (cathode ray tube exp.)

and quantified electron’s charge by Rob Millikan (oil drop exp.)

Nuclear Atom Model

based on discovery of nucleus, rest of atom is open space (Rutherford, gold foil exp.)

nucleus

dense core of heavier protons and neutrons

isotopes

same # protons but dif. # neutrons resulting in dif. mass numbers

cations

positively charged ions formed by loss of electrons

anions

negatively charged ions formed by gain of electrons

atomic mass/wt (AW)

avg. mass of isotopes, weighted according to natural abundance

mass spectrometer

measures particle mass (beam ray)

1mol = 6.02 × 10²³

Avogadro’s Number

molar mass (amu)

mass in grams in 1 mole of a substance (g/mol

light

electromagnetic radiation, “radiant” energy

electromagnetic radiation

has both wave and particle properties

wavelength

λ, peak-to-peak distance (nm)

frequency

ν, number of cycles per second (1/s, Hz)

speed (of light)

c (m/s)

quantum

energy packet in which a system can gain or lose energy only in whole-humber multiples

photon

quantum of electromagnetic radiation

Planck’s constant

h (constant for quantum scale, energy packets)

frequency(v) and energy (E)

wavelength is inversely proportional to…

750-400nm

range of visible light v

Cr , Cu, Mo, Ag

elements with anomalies in e- config.