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Chem test 2

Terms in this set (65)

Define atom
the smallest part of an element that still has all characteristics of that element
what are the particles that exist inside the nucleus
protons and neutrons
compare the relative locations and masses of each of the three subatomic particles within the atom
proton ad neutron in the nucleus 1 amu
electrons in the electrons cloud 1/1840 amu
How was dalton's theory of the atom different from what we know now?
Dalton's Theory - part that is different from what we now know:
all elements are composed of indivisible atoms (not true)
As a result of Rutherford's discovery of the nucleus of the atom, what is currently believed to be true about the nucleus of the atom and the remainder of the atom?
Rutherford states that (1)the nucleus is very small but dense and the most massive part of the atom (2)the rest of the atom is BIG and mostly empty space
What info do we get from the atom number of an element
atomic number = number of protons
What info do we get from the mass number of an element
mass number = number of protons and neutrons added together
Explain, in detail, how to calculate the number of neutrons in an atom of an element
Neutrons are calculated by subtracting the atomic number (protons) from the mass number (protons and neutrons).
What is an isotope?
atoms of the same element that have different masses (due to differing numbers of neutrons in the nucleus)
With isotopes of the same element, what remains the same and what's different?
Isotope - what remains the same is the number of protons (atomic number); what changes is the number of neutrons
In the isotope Carbon-14, what does 14 represent?
The 14 represents the mass number
What's the atomic mass of an element?
. Atomic mass is the mass of one atom of an element. This is the weighted average of the relative percent abundances and atomic masses of each isotope.
Define the term period as related to the periodic table
horizontal row in the periodic table
Define the term group or family as related to the periodic table
vertical column in the periodic table
Who was Dmitri Mendeleev?
Dmitri Mendeleev was the creator of the first periodic table. (2)Dmitri was the first to organize elements (close to 70 of them). He did this by atomic mass and vertical columns with elements of similar characteristics.
How is the modern periodic table organized?
Modern periodic table is arranged by atomic number.
What is an ion?
An ion is a charged atom or group of atoms. Ions are formed from the gain or loss of electrons.
What is a cation
A cation is a positively charged ion.
What is an anion
An anion is a negatively charged ion.
List three characteristics of molecular compounds that distinguish them from ionic compounds
molecular compounds (1)made of two or more nonmetals (2)Use Greek Prefixes in the name (3)have a low melting and boiling point compared to ionics (4)most are liquids or gases at room temperature
List at least three characteristics of ionic compounds that distinguish the from molecular compounds
ionic compounds (1)made of one metal and one nonmetal or polyatomic ion (2)DO NOT use Greek Prefixes in the name (3)have high melting and boiling points compared to moleculars (4)most are solids at room temperature
Define formula unit
The lowest whole-number ratio of ions in the compound. (no separate molecular units, just an array of ions which is continuous)
Define the law of multiple proportions and provide an example of two compounds that illustrate this law
states that compounds may contain the same exact elements but if the number of atoms of the individual elements are different, the compounds are also different. Examples: H2O and H2O2; CO and CO2
What are polyatomic ions
Ions containing more than one type of atom
What are the two most common suffixes for a polyatomic ion
"ate," and "ite"
what's the suffix used in naming all binary molecular and ionic compounds
"ide"
what do the greek prefixes in the name of a compound tell us
Greek prefixes tell the number of atoms of that particular element.
What do the roman numerals in the formula of a compound tell us
Roman Numerals tell the charge.
What type of compound uses Greek prefixes in the name
Molecular uses Greek prefixes.
what type of compound uses roman numerals in the formula
IONIC COMPOUNDS
what's a subscript
used in a chemical formula and is written to the lower right of the symbol to tell the number of atoms of an element; it is a number.
what are the similarities and differences between a molecular formula and a formula unit
Molecular Formula - shows the kinds and numbers of atoms present in a molecule of a compound; it is the chemical formula of a molecular compound.
Formula Unit - show the lowest whole-number ratio of ions in the compound; the chemical formula for an ionic compound
What are the similarities and differences between molecular compounds and ionic compounds
Formulas both contain symbols for the elements; names for both (when binary) will contain the suffix "ide" on the second element
p,n,e 78^Sr
p+ = 38; n˚ = 40; e- = 38
179Ra+2
p+ = 88; n˚ = 91; e- = 86
34P
p+ = 15; n˚ = 19; e- = 15
100I-1
p+ = 53; n˚ = 47; e- = 54
238U
. p+ = 92; n˚ = 146; e- = 92
10N-3
p+ = 7; n˚ = 3; e- = 10
Ca
metal
Br
nonmetal
Fe
Metal
Mo
metal
Xe
nonmetal
B
nonmetal
Na2(S04)
ionic
C2H6
molecular
PBO2
ionic
PCI5
molecular
K(NO3)
ionic
N2O4
molecular
Na2(SO4) name
sodium sulfate
C2H6. name
dicarbon hexahydride
PbO2 name
. lead(IV)oxide
PCI5. name
phosphorus pentachloride
K(NO3). name
potassium nitrate
N204. name
dinitrogen tetraoxide
Lithium dichromate
Li2(Cr2O7)
Sulfur hexafluoride
SF6
Dihydrogen Monoxide
H2O
Ammonium nitrate
(NH4)(NO3)
Hydrogen sulfate
H2(SO4)
iron 3 sulfide
Fe2S3
tetracarbon decahydride
C4H10
Copper 2 bromide
CuBr2
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