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Chem 105 Exam 1
Term | Definition |
---|---|
Chemistry | is the study of matter and the changes it undergoes |
Matter | is anything that has mass and occupies space |
Scientific Method Process | 1. Observation and description of a phenomenon 2. Hypothesis 3. Use of the hypothesis to predict the existence of other phenomena, or explain the results of new observations 4. Experimental tests of the predictions |
Scientific Method | fail-safe method for analyzing observations Observation - Hypothesis - Experiments (prove or disprove) - Publication (further experiments) - Conformation - Application |
hypothesis | educated guess |
theory | A hypothesis that has been tested with a significant amount of data |
law of nature | a generalization that describes recurring facts or events in nature |
Physical Sciences | chemistry, physics, geology, and astronomy |
biological sciences | botany and zoology |
Physics | sciences of matter and energy and of interactions between them |
Geology | study of origin, history, and structure of the earth |
Astronomy | is the scientific study of matter in outer space. |
Botany | science or study of plants |
zoology | deals with animals and animal life including the study of structure, physiology, development, and classification of animals |
Physical Chemistry | chemistry is applied to physics |
geochemistry | chemistry of the earth is studied |
biochemistry | chemistry of biological entities |
Basic science | is research without the goal of a practical application |
Applied Science | science of applying the knowledge gained from one or more natural scientific fields to practical problems |
Macroscopic | matter large enough to be seen by the naked eye |
Microscopic | requires the aid of a microscope or similar instruments to be viewed |
submicroscopic | matter is too small to be seen even with the most powerful microscopes |
Mass | quantity of matter in an object |
weight | force that results from the attraction between matter and the earth |
property | anything that can be observed or measured about a sample of matter |
intensive | independent of the sample size such as concentration, density, and boiling and freezing points. |
extensive | depends on the size or amount of the sample like mass, volume and energy |
elements | substances containing only one kind of atom |
atom | smallest unit found in elements |
pure substances | matter with fixed composition at the submicroscopic level |
compounds | decomposed into simpler substances by normal chemical means |
mixtures | a combination of substances |
heterogeneous | which different substances can easily be seen within the mixture |
homogeneous | COMPOSED OF IDENTICAL PARTS; UNIFORM IN COMPOSITION |
solution | a mixture of different solutions |
chemical properties | describe the tendency of a material to react and change into a different compound |
physical properties | can be measured without changing the identity of the material |
physical change | since it resulted in a change in only physical not chemical identity |
chemical change | change in which a part of the substance is being converted into a different kind of matter |
chemical reaction | the process in which one or more substances are converted to one or more different substances |
reactants | substances that undergo a change in chemical reaction |
products | substances that are formed in a chemical reaction |
molecule | smallest unit of a chemical compound that can exist independently |
diatomic | molecules formed from two atoms |
energy | is defined as the ability to do work |
potential energy | energy in storage by virtue of position or arrangement |
kinetic energy | is the energy of objects in motion |
chemical formula | written combination of element symbols that represents the different atoms combined in a chemical compound |
subscripts | are used in chemical formulas as numbers written below the line to show the numbers or ratios of atoms in a compound |
molecular formulas | are chemical formulas that represent molecules with atomic symbols an subscripts |
structural formulas | chemical formulas that show the connections between atoms in molecules with straight lines |
chemical equations | describe the identities and relative amounts of both reactants and products in a chemical reaction |
qualitative | not numerical but are used to identify the chemical species involved |
quantitative | determine the amount of product formed or the amount of reactants used in a chemical reaction |
accuracy | agreement of the measured value with the true value of the same quantity. |
John Dalton | Creator of Dalton's atomic theory (1766-1844) |
law of constant composition | all samples of a pure substance contain the same elements in the same proportions by mass |
law of multiple proportions | states that the masses of one element will always combine with a fixed mass of the second element |
law of conservation of mass or matter | there is no detectable loss or gain in mass when a chemical reaction occurs |
Nucleus | contains 99% of the mass and is found in the center of the atom |
nuclear model of the atom | protons and neutrons are found in the nucleus of the atom and the electrons are located in a three dimensional area around at a relatively large distance away from the nucleus |
atomic number | number of protons in an atom rep. by letter Z. |
mass number | number of protons plus the number of neutrons in the nucleus of an atom and is represented by the letter |
Isotopes | different atoms of the same element that contain different numbers of neutrons (same z, different A) |
ions | new charged species |
anions | gain electrons, becoming negatively charged |
cations | lose electrons, become positively charged |
Atomic mass number (u with line coming down at beginning | established to compare the mass of any atom to that of the carbon 12 isotope |
atomic weight | weighted average mass in atomic mass units the isotopes of an element |
waves | repeat at regular intervals of time and distance |
amplitude | maximum height of the wave |
wavelength | is the distance between one peak and the next |
frequency | is the number of waves that pass a particular point in a given time period (Hz 1/s) |
electromagnetic radiation | consist of oscillating electric and magnetic fields perpendicular to one another |
constructive interference | positive effect light rings |
destructive interference | negative effect, dark rings |
excited state | higher energy state |
ground state | lower original state |
principle shells | discrete energy levels |
niels bohr | 1911, he showed that electrons in atoms were limited to these energy levels or shells 1st shell=2 electrons, 2nd shell=8 electrons, 3rd shell=18 electrons, 4th shell=32 electron |
atomic orbital | is a region of 3-deminesional space where electrons exist around the nucleus |
sub shells | each energy shell consists of a certain number and type of orbitals grouped into Ex: S,P,D,F |
aufbau principle | electrons are added to atoms one at a time to available orbital with the lowest energy first |
electron configuration | distribution of these added electrons |
Valence orbitals | orbitals of the outermost or highest energy level and partially filled subtle of lower energy |
valence electrons | electrons found in these valence orbitals- most involved in chemical reactions |
period | each row of the table 1-7 |
groups | tio of the table |
metal | substance that is malleable, has luster, and is a good conductor of electricity |
metalloids | fall along the actual line separating the metals from the nonmetals and share certain properties of both |
semi-conductors | weak conductors of electricty |
transition metals | showing a regular decrease in metallic behavior IIIB |
inner transition metals | are found at the bottom of the table |
name for inner transition metals | lanthanides (Ce-Lu( and actinides (Th-Lr) |
alkaline earth metals | Group 1A slightly less reactive than the alkali metals |
alkali metals | Group 2A very reactive, especially with water and must be handled carefully |
halogens | Group 7A among the most reactive nonmetals with reactivity's decreasing down the group |
Noble gases | VIIIa Inert gases because of their seemingly nonreactive behavior |
1s^1 | referring to electorn configuration, hydrogen |
2s^1 | lithium |
ionization energy | amount of energy needed to remove an electron and increases from left to right and decreased from top to bottom on the periodic table |
Ernest Rutherford Gold Foil Experiment | atom is mostly empty space. Over 99% of mass is found in a very small region in the nucleus. lead to modern view of the atom |
Representative Elements | S and P blocks |
Transition Elements | D and F blocks |
Atomic Radii | Gets smaller from left to right Gets larger from top to bottom |
Ionic Radii | Cations are smaller than neutral atoms, anions are larger |
Extra Credit: Where did the W on the periodic table for tungsten come from? | Wolfram, Tungsten's original name. |
John Dalton | 1. all matter is made up of small indivisible particles called atoms 2. atoms of the same element are identical; atoms of different element have different properties 3. compounds are formed when atoms of different elements combine in small whole numb |