Semester 1 Final Flashcards
What is the chemical formula for ozone?
O3
What does the ozone layer do?
Protects living things on Earth from ultra violet waves
What are the two types of ozone?
Air-naturally occurs in the upper atmosphere (good)
Ground- created by exhaust and aerosol (large amounts are toxic)
How is ozone being depleted?
Chlorofluorocarbons (CFCs) and nitrous oxide
Independent variable
Value scientists plan on changing
Dependent variable
Value that changes in response to the change in the independent variable
Constant
Values that must stay the same throughout the experiment
Control
Standard used for comparison
Qualitative data
Information describing color, odor, shape, or some other physical characteristic (not able to be measured)
Quantitative data
Numerical information describe how much, little, big, tall, or fast (measurable Ex: height, length, volume)
Theory
Explanation of natural phenomenon based on many observations and investigations over time
Scientific law
Relationship in nature supported by many experiments
Difference between a theory and a law
There are no exceptions to laws; theories can be proved wrong
How do you calculate significant figures when multiplying/dividing?
Number of the least significant figures of the numbers being multiplied/divided= number of significant figures in answer
Ex:124.0 x 2.4= 297.6= 300
How do calculate significant figures when adding/subtracting?
Where the shortest number ends= where significant figure of product ends
Ex: 35.01 + 72.3+ 61= 168.31= 168
How to determine significant figures when measuring
Sig figs go to the closest measuring mark, then a guess
Ex: measuring cm: 55.40
Chemical change
Change that involves one or more substances changing into new substances
Ex: burning, reaction, neutralization
Physical change
Change that alters a sample without changing its composition
Ex: tearing, grinding, mixing
Accuracy
How close a measured value is to the accepted value (right answer)
Precision
How close a series of measurements are to eachother rather than the accepted value (May be wrong, but consistently wrong)
Density
Amount of mass per unit of volume
D= m/v
Label for density?
G/cm cubed or g/mL
(1cm cubed= 1 mL
Slope formula?
x2-x1
Between what numbers must the coefficient be in scientific notation?
1 and 10
What is the exponent when you move the decimal to the right?
Negative
What is the exponent when you move the exponent to the left?
Positive
Mixture
Combination of 2 or more pure substances in which each pure substance retains its individual chemical properties
Two kinds of mixtures?
Heterogeneous and homogeneous
Heterogeneous mixture
Mixture that doesn’t blend smoothly throughout and individual substances remain distinct
Ex: chez mix, pepperoni pizza
Homogeneous mixture
Mixture that has a constant composition throughout (also called solution)
Ex: black coffee, salt water
Intensive properties
Property that remains the same no matter how much of the substance is present
Ex: density, color, flammability, solubility
Extensive properties
Property that is dependent upon the amount of substance present
Ex: length, mass, volume
States of matter
Physical forms in which all matter exists on earth (physical property)
Name the three states of matter
Solid, liquid, gas
Solid
Has its own definite shape and volume, is incompressible, and expands only slightly when heated
Ex: ice
Liquid
Flows, has constant volume, and takes the shape of the container
Ex: water
Gas
Flows to conform to shape of container, fills containers entire volume, and is easily compressed
Ex: water vapor
Compound
Made up of two or more different elements that are combined chemically
-type of pure substance
Ex: salt, water, sugar
What four things are shown in a box on the periodic table?
- atomic number
- chemical symbol
- name of element
- mass number(AVG mass of all known isotopes)
Contribution to the Atomic Theory: Chadwick
Discovered the neutron
Contribution to the Atomic Theory: Thompson
Discovered the electron and charge to mass ratio (plum pudding model)
Contribution to the Atomic Theory: Rutherford
Discovered atoms were mostly empty space, which led him to discover the proton and nucleus
Contribution to the Atomic Theory: Bohr
Created quantum model for the hydrogen atom to explain its atomic emission spectrum
Created ground state (lowest energy level) as well as quantum numbers.
-models flaw: didn’t explain AES for any other element
Electron
Negatively charged subatomic particles
-located outside nucleus
Nucleus
Small, densely packed center of an atom; made of protons of neutrons
Protons
Positively charged subatomic particles
- located in nucleus
- mass: 1amu
Neutron
Subatomic particle with no charge
- located in nucleus
- mass: 1amu
How to find mass number of an element?
- Multiply the mass of each isotope by its occurrence percentage
- add the product of each isotope to find the final mass number
What does the isotope symbol tell you?
Element and symbol, atomic mass (top left), and atomic number (bottom left)
Crest
Highest point on a wave
Trough
Lowest point on a wave
Wavelength
Shortest distance between equivalent points on a continuous wave (crest to crest, trough to trough)
Amplitude
Waves height from origin to crest/trough
Frequency
Number of waves that pass a given pint per second
- symbol: v
- measured in hertz (Hz)
Longer wavelength=???
Lower frequency
Like a spring
Short wavelength=???
Higher frequency
Like a spring
Electromagnetic radiation
Form of energy that exhibits wavelike behavior as it travels through space
Electromagnetic spectrum (EM spectrum)
Includes all forms of electromagnetic radiation with only difference in types of radiation being in wavelength and frequency
Types of EM radiation (7)
Lowest to highest frequency/ highest to lower wavelength
Radio Microwave Infrared Visible light (red: lowest frequency violet: highest frequency) UV X-rays Gamma rays
Valence electron
Electrons in the outermost energy levels
What do valence electrons determine?
Bonding, reaction, and oxidation number
Valence electrons in each group
Group 1(Alkali metal): 1 Group 2(alkaline earth metals): 2 Group 3-12: multi alert except for Cd, Ag, and Zn Group 13(boron group): 3 Group 14(Carbon group): 4 Group 15(nitrogen group): 5 Group 16(chlacogens): 6 Group 17(Halogens): 7 Group 18(Noble gases): 8 (except He: 2)
Electron dot structure
Element symbol plus dots signifying number of valence electrons
Oxidation number
Positive/negative charge of an atom as a result of forming an ion
What groups form positive ions(cation)?
Any group with less than 4 valence electrons
Group 1-13
What groups form negative ions(anion)?
Groups 15-17
What is the oxidation number for the carbon group?
Positive or negative 4 (depends what it’s being bonded with)
Why don’t noble gases have oxidation numbers?
Huey have a full set of outer level electrons, so they don’t react with any other element
Oxidation numbers of each group
1: +1
2: +2
3-12: multivalent
13: +3
14: - or + 4
15: -3
16: -2
17: -1
What transition metals have fixed charges?
Silver (Ag): +1
Cadmium (Cd) and zinc (Zn): +2
Electron configuration
Arrangement of electrons in an atom
Aufbaus rule
Each electron occupies the lowest energy orbital available
Paulis exclusion principle
A max of 2 electrons can occupy a single atomic orbital but only of the electrons have opposites spins
Hunds rule (bus rule)
Single electrons with he same spins must occupy each energy level before additional electrons with opposite spins can occupy the same orbital
(Each one gets 1 before any get 2)
Sub levels: orbitals and max electrons
S: 1 orbital; holds up to 2 electrons
P: 3 orbitals; holds up to 6 electrons
D: 5 orbitals; holds up to 10 electrons
F: 7 orbitals; holds up to 14 electrons
What groups do each sub level make up?
S- group 1 and 2 plus Helium
P- 13-18 except helium
D- 3-12
F- lanthanides and actinides
Noble gas configuration
Last noble gas in brackets then he rest of the configuration
Ex: aluminum- [Ne]3s23p1
Orbital diagrams
Represents each electron in every orbital/sub level
- arrows must point opposite ways (Pauli)
- lowest level must be filled before moving on (Aufbau)
- each one must get 1 before any get 2 (Hund)
Groups
Columns
Periods
Rows
Ionization energy
Energy required to remove an electron from an atom
Decreases down group, increases across period
Atomic radius
Distance across an atom
Increases down group decreases across period
Electron negativity
Relative ability of an atom to attract electrons
Decreases down group, increases across period
Characteristics of metals (5)
Good conductors, malleable, ductile, high melting and boiling points, shiny
Characteristics of no metals (5)
Generally gases, dull, brittle, poor conductors, low melting and boiling points
Characteristics of metallics
Characteristics of both metals and nonmetals
What did Dmitri Mendeleev contribute to the periodic table?
Arranged elements in increasing atomic mass
-left room for undiscovered elements and actually predicted some of their properties
What did Henry Mosley contribute to the periodic table?
Discovered relationship between atomic number and number of protons and arranged elements by increasing atomic number
Alpha particle
Particle with two protons and two neutrons, with and +2; equivalent to a helium-4 nucleus and is emitted by radioactive decay
Alpha radiation
Radiation made up of alpha particles; deflected towards negatively charged plate when directed between two electrically charged plates
-blocked with sheet of paper
Beta particle
High speed electron emitted during radioactive decay
Beta radiation
Radiation made up of beta particles; deflected toward positively charged plate when directed between two electrically charged plates
(Moves more than alpha radiation because it has less mass)
-blocked with sheet of lead
Gamma ray
High energy radiation with no mass and no charge; not deflected toward either plate and usually accompanies alpha and beta radiation
- accounts for most energy lost during radioactive decay
- blocked by block of lead
Where does the radiation go in a decay equation?
Product side (right)
Where does radiation go in a capture equation?
Reactant side (left)
Chemical bond
Force that holds two atoms together
Two types of chemical bonds
Covalent and ionic
Covalent bond
Formed by the sharing of electrons (between two non metals)
Ionic bond
Formed by the transfer of electrons (between cation and anion/ metal and nonmetal)
How to name a binary ionic compound
Metal then nonmetal with -IDE ending; CHARGES MUST MATCH!
Ex: magnesium sulfide: MgS
How to name multivalent ionic compounds
Metal (Roman numeral) then nonmetal with -IDE ending; CHARGES MUST MATCH!
Any metal 3-12 have multiple oxidation numbers indicated by Roman numeral
Ex: copper (I) sulfide: Cu2S
How to name polyatomic ionic compounds
Metal (and Roman numeral if needed) then polyatomic ion. CHARGES MUST MATCH! Parentheses if adding subscript to polyatomic
-all polyatomic ions are negative except ammonium (NH4)
Ex: aluminum nitrate: Al(NO3)3
How to name molecular compounds
Covalent: first nonmetal with prefix (unless subscript is one) then second nonmetal with prefix
Ex: disulfur pentoxide: S2O5
How to name hydrates
Hydrate: compound containing water
Normal ionic name + H2O with a prefix
Ex: aluminum nitrate octahydrate: Al(NO3)3:8H2O
:= dot
Naming rules for acids (3)
MUST HAVE HYDROGEN FIRST! end in -ide: hydro\_\_\_\_\_\_\_ic acid Ex: HBr: hydrobromic acid (charges must match) end in -ate: \_\_\_\_\_\_ic acid Ex: H2SO4: sulfuric acid end in -ite: \_\_\_\_\_\_ous acid Ex: HClO2: chlorous acid
