Exam 1 Flashcards
Atomic Theory
- Everything is made of atoms
- Atoms are the smallest whole unit of am element
- Atoms combine with like and different atoms to form molecules
Chemical Reaction
- Chemicals interact to form different substances with different properties
- Reordering of atoms
Chemical Property
- describes a chemical change that a substance undergoes
- 2 types: intensive and extensive
Elements
- Substances that cannot be decomposed into simpler materials by chemical reactions
- Atoms all contain the same number of protons
Compound
- Substance formed from two or more different elements in which the elements are always combined in the same fixed proportions by mass
Pure Substances
- Element or compound
Mixture
- Substance with variable composition
- Homogenous or heterogenous
Homogenous
- Same properties throughout sample
- Solution
Heterogenous
- Two or more phases with different properties
- i.e. oil and vinegar
Solution
Homogenous mixture
Mixture vs. Compound
No chemical change in a mixture. Chemical change in a compound.
Law of Conservation of Mass
Mass is conserved in chemical reactions
Law of Definite Proportions
In a given chemical compound, elements always combine in the same proportion by mass
Dalton’s Atomic Theory (know gist, do not need to memorize)
- Matter is made of atoms
- Atoms are indestructible and do not break apart
- In pure element samples, atoms identical in mass and properties
- Atoms of different elements differ in mass/ properties
- When atoms of different elements combine to form compounds, new and more complex particles form. However, in a given compound the constituent atoms are always present in a fixed numerical ratio.
Law of Multiple Proportions
Small whole numbers in ratios of elements in compounds
Atomic Mass
- mass of a single atom
Atomic Weight
- Listed on the P.T.
- Weighted average of masses of naturally occurring isotopes
Subatomic Particles
The stuff that makes atoms…. protons, electrons, neutrons
Atomic Number
- The number of protons in an atom
- denoted by ‘Z’
Mass Number
#p+#n denoted by 'A'
Mass Number
#p+#n denoted by 'A'
Periods
- Rows of periodic table
Groups
- Columns of periodic table
- Numbered or roman-numeral-ed
Alkali Metals
- Group IA (1)
+1
Alkali(ne) Earth Metals
- Group IIA (2)
+2
Halogens
- Group VIIA (17)
- 1
Noble Gases
- Group VIIIA (18)
- do not form ions
Metalloid
Elements with properties that lie between those of metals and nonmetals. Tend to be semiconductors.
Metal
- Good conductor of electricity
- Shiny surface
- Malleable
- Ductile
- Solid at room temp (except Mercury)
Nonmetal
- Does not conduct electricity
- Not malleable
- Not ductile
Chemical Formulas
- Chemical symbols used to represent atoms of elements present
Free Element
- Element not combined with another - not in a compound
- All free nonmetal elements EXCEPT NGs exist as diatomic
Diatomic Molecules
Composed of 2 atoms each
H2,N2,O2,F2,Cl2,Br2,I2
Hydrates
- Compounds whose crystals contain water molecules in fixed ratios
Dehydration
Removal of water
Chemical Equations
- Describes what happens when a chemical reaction occurs
- MUST BE BALANCED
Energy
- Something an object has if the object is able to do work
Kinetic Energy
- The energy an object has while moving
Kinetic Energy Equation
KE = 1/2mv^2
Potential Energy
- The energy an object has that can be changed to KE
- Stored energy
- PE of chemicals = chemical energy
Law of Conservation of Energy
Energy cannot be created or destroyed. It can only be transformed from one form to another
Temperature
- Proportional to the average KE
Heat
- Thermal energy
Molecule
- Electrically neutral particle consisting of two or more atoms
- Held together by chemical bonds which are electrical in nature
Molecular Formula
- Denotes the number of each type of atom in a molecule
Hydrides
- Compounds that form with hydrogen
Hydrocarbons
- Compounds of H and C
- Usually follow rule of C(n)H(2n+n)
Alkane
- First six members of hydrocarbon series
Inorganic Compounds
Do not derive from hydrocarbons
Binary Compounds
- Compounds composed of 2 different elements
Ion
charged particle
Ionic Compound
- Formation involves electron transfers
- Formed when metals react with nonmetals
- Neutral charge
- Do not call them molecules
- In lattice form
Formula Unit
- A particle that has the composition given by chemical formula…. ie. NaCl
Cation
Positive ion
Anion
Negative ion
Writing Ionic Compounds
- Positive ion first in formula
- Subscripts produce neutral formula unit
- Lowest whole # ratio
- Ion charges not included in finished formula
Post-Transition Metals
Metals on the periodic table following a row of transition metals
Polyatomic Ions
- Ions composed of 2 or more atoms liked by the same kind of bonds that hold molecules together
Proton
- Subatomic particle
- Positive charge
- Massive (has mass)
- Inside the nucleus
Neutron
- Subatomic particle
- Neutral charge
- Massive (has mass)
- Inside nucleus
Electron
- Subatomic particle
- ## Negative charge
Electron
- Subatomic particle
- Negative charge
- Negligible mass
- Outside nucleus
Inside vs. Outside Nucleus
Inside: where the mass is
Outside: where the volume is
Transition Metals on the P.T.
Periods 4-7, groups 3-12 EXCEPT
P6,G3 and P7G3
Actinide
Bottom period beginning in Ac
Lanthanide
Second to bottom period beginning with La
Non Metals on P.T.
H,C,N,O,P,S,Se
Metalloid PT
B, Si, Ge, As, Sb, Te, Po
States of Matter
Solid, liquid, gas
Solid most dense
Gas least dense
Mono
1
Di
2
Tri
3
Tetra
4
Penta
5
Hexa
6
Hepta
7
Octa
8
Nona
9
Deca
10
Ionic Bonds
- Form because of electrostatic attraction between oppositely charged ions
- Metal and nonmetal
Covalent Bonds
- Sharing of electron in bond
- Between nonmetal and nonmetal
Ammonia
NH3
not ammonium
Hygroscopic
Absorbs water from the air
Precipitate
Solids formed by a chemical reaction that drop out of solution
Product
What is formed in a chemical reaction
Reactant
What reacts in chemical reaction
Aqueous
- aq
- in solution
Law of Constant Composition
Same compound = same composition.
Mass percent
Mass element / compound
Bonding
How we describe the way atoms are held together in atoms or compounds
When bonds are formed, energy is….
RELEASED.
When bonds are broken, energy is….
consumed.
Lower energy state
more stable
Binary Compound
- contains only 2 elements
- only ionic
Allotrope
Same element or compound in a different state
In equations, metals tend to be
solid
In equations, diatmoics tend to be
gas
In equations, pure ionic compounds tend to be
solid
In equations, pure ionic compounds with water are
aq
In equations, hydrates are
solid
Empirical Formula
Simplest, most reduced whole number ratio of atoms present in a chemical
Mass Percent
(mass of element/mass of compound)*100
Combustion
Reaction of substance and oxygen initiated with heat. Gives off more heat, CO2 and H2O.
Avogadro’s Number
6.02x10^23
Mole in words
Don’t worry about it. Just understand it.
Molar Mass
# grams in 1 mole of substance - Sum of atomic masses of atoms in substance (in proper proportion)
