Chem 1211 chap 1-2 – Flashcards
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Unlock answers| Chemistry |
| is the study of the composition, structure, and properties of matter, and the changes, which it under goes |
| Matter |
| is anything that has mass and takes up space |
| Chemical |
| a type of matter, that always has the same composition and properties wherever it is found |
| Elements, Atoms |
| Matter is composed of _________, which is composed of _______ |
| A Chemical Reaction |
| One substance changes to another by reorganizing the way the atoms are attached to eachother |
1. Observations (collecting data) 2. A Prediction (formulating a hypothesis 3. Performing experiments |
| 3 Fundamental elements of the Scientific Method |
| Qualitative |
| Some observations that are simple descriptions about the characteristics or behavior |
| Quantitative |
| Some oberservations involve both number and units (measurements) |
| Hypothesis |
| a possible interpretation or explanation for an observation |
| Law |
| Summarized what happens |
| Theory (Model) |
| An attempt to explain why it happens, Set of tested hypotheses that vgives an overall explanation of some natural phenomenon |
| A Scientific Law |
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| how and why |
| The Scientific Method is used to create laws and theories that help explain ___________ the world behaves the way it does. |
| 1 cm 3 = 1 cc |
| 1 mL = |
| 103 m = 1 km |
kilo = 1000 What is the Scientific Notation? |
0.1 or 10-1 1 dL = 10 -1 1 L = 10 dL |
| deci (d) = |
0.01 or 10-2 1 cm = 10 -2 1 m = 100 cm |
| centi (c) |
0.001 or 10 -3 1 ms = 10 -3 s 1 s = 103 or 1000 ms |
| milli (m) = |
0.000 001 or 10 -6 1 μg = 10-6 g 1 g = 106 μg |
| micro (μ) = |
kg m L or m3 s K for chemistry or °C |
The Fundamental SI Units Mass Length Volume Time Temperature |
| Accuracy |
| How close a measurement comes to the real or "true" value |
| Precision |
Reproducibility of a measurement How closely measureents agree with one another |
2 3 4 |
How many sig figs are in 50. L 25.0 °C 16.00 g |
2 3 |
How many sig figs are in 4.0 x 105 m 5.70 x 10-3 g |
1 2 |
How many sig figs are in 0.0004 lb 0.075 m |
| Measured, Exact |
| Only ________ numbers take into account sig figs. _______ numbers are ignored when considering sig figs. |
| multiplying or dividing |
| When ________ or _________ you should have the same number of sig figs in the answer as the measurement with the fewest sig figs. |
| adding or subtracting |
| When ______ or _______ you should have the same number of decimal places in the result as the measurement with the fewest decimal places |
| TK = TC + 273.15 |
| Formula to convert °C to K |
| TC = TK - 273.15 |
| Formula to convert K to °C |
TC = (TF - 32 °F) . 5 °C 9 °F |
| Formula to convert °F to °C |
TF = TC . 9°F + 32°F 5°C |
| Formula to convert °C to °F |
| 1.0 g/mL |
| The Density of water 4 °C = |
| Solids |
a definite shape and vol. particles packed together in fixed arrangement particles that move very slowly |
| Liquids |
a indefinite shape, definite vol. same shape as container particles that are close together, but have ability to move around slowly |
| Gases |
an indefinite shape and vol. same shape and vol. as container particles that are far apart and move very fast
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| Pure Substance |
| A ______, classified as matter with a specific composition, an element when composed of one type of atom, a compound when composed of two or more elements combined in a definite ratio |
| mixture |
A ________ is matter that consists of
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| Homogeneous Mixture |
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| Heterogeneous Mixture |
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| Physical Properties |
A characteristic of the substance such as color, shape, odor, luster, size, melting point, and density -directly observable |
| Chemical properties |
A characteristic that indicates the ability of a substance to form another substance - paper can burn, iron can rust, and silver can tarnish |
| Physical Change |
| A change in a physical property that retains the identity of the substance: a change of state, size, or shape |
| Chemical Change |
| A change in which the original substance is converted to one or more new substances: paper burns, iron rusts, silver tarnishes |
Law of Conservation of Mass Antoine Lavoisier 1743-1794 |
In a chemical reaction, matter is neither created nor destroyed total mass of reactants = total mass of products |
Law of Definite Proportions Joseph Proust (1754-1826) |
| All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements |
Law of Multiple Proportions John Dalton |
When 2 elements form two diff compounds can be expressed as a ratio of small whole numbers A3B4 |
| JJ Thomson Experiment (1898-1903) |
| Which experiment postulated the existence of electrons using cathode-ray tubes. Early experiments showed that the atom composed of only - charged particles but overall charge on atoms neutral |
| Ernest Rutherford gold-foil experiment |
In ________ experiment, + charged particles
|
| Protons |
| In the nucleus, positive charge (+1), mass of 1 am |
| Neutrons |
| In the nucleus, no charge, mass of 1 am |
| Electrons |
Outside of the nucleus, negative charge (-1), mass of 1/2000 amu (basically zero) |
| Protons |
| atomic number = the # of |
| Protons, Neutrons |
| Mass Number = # of ___ + # of ____ |
| Alkali metals |
| Group 1A(1): |
| Alkaline earth metal |
| Group 2A(2): |
| Chalcogens |
| Group 6A (16): |
| Halogens |
| Group 7A (17): |
| Noble gases |
| Group 8A (18): |
| Transition Elements |
| Group 1B-8B (3-12): |
| Lanthanides |
| Elements 58-71: |
| Isotopes |
are identified by their mass numbers have diff number of neutrons |
Bottom # = atomic number = # protons #electrons Top # = mass number = # protons + # neutrons |
| [image] |
| Ionic Bonds |
Metals atoms bonded to Non Metals atoms electrons have been transferred between atoms, resulting in oppositely charged ions
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| Covalent Bonds |
two atoms share some of their electrons - generally found when nonmetal atoms bonded together |
| Periodic Law |
| Mendeleev (1st Periodic Table) _________ - When the elements are arranged in order of increasing atomic number, certain sets of properties recur periodically |
| Metals |
solid at room temp. except Hg reflective surface - shiny conduct heat conduct electricity malleable - can be shaped ductile - drawn or pulled into wires lose electrons and form cations in reactions |
| Nonmetals |
found in all three states poor conductors of heat and electricity Solids are brittle gain electrons in reactions to become anions upper right on the table except H
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| Metalloids |
show some properties of metals and some of nonmetals also known as semiconductors |
Form 2 or more positive ions.
Zn2+, Ag+, Cd2+ |
Most transition metals and Group 4 metals with the exception of _________ |
