chemistry chapter 3 and 4

write the electron configuration for Ge and identify the core and valence electrons

- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 - core: 1s2 2s2 2p6 3s2 3p6 3d10 - valence: 4s2 4p2

energy ordering of a number of orbitals:

- because of penetration the sublevels of each principal level are not degenerate for multielectron atoms - in the 4th and 5th principal levels, the effects of penetration become so important that the 4s orbital is lower in energy than the 3d orbitals and the 5s orbital is lower in energy than the 4d orbitals - the energy separations between one set of orbitals and the next become smaller for 4s orbitals and beyond, and the relative energy ordering of these orbitals can actually vary among elements. these variations result in irregularities in the electron configurations of the transition metals and their ions

exceptions in the trend for first ionization energy:

- boron's is smaller than beryllium (caused by change from s to p block) - Aluminum and Gallium - nitrogen and oxygen - S and Se -Na and Cl ?

properties of nonmetals:

- can be solid, liquid or gas - poor conductors of heat and electricity - gain electrons when they undergo chemical changes - form negatively charged ions

properties of metal:

- good conductors of heat and electricity - malleable - ductility shiny - they lose electrons when they undergo a chemical change -form positively charged ions

2 different types of shielding:

- the shielfing of the outermost electrons by the core electrons and - the shielding of the outermost electrons by each other

properties of ionic compounds:

-high melting and boiling points - tendency not to conduct electricity as solids - and their tendency to conduct electricity in water

predict the charges of sulfur

-monoatomic - [Ar] 1s2 2s2 2p6 3s2 3p6

predict the charges of Al

-monoatomic - [Ne] 1s2 2s2 2p6 3s2 3p6

3 key concepts associated with the energy of an electron in the vicinity of a nucleus:

1. columb's law, which describes the interactions between charged particles 2. shielding, which describes how one electron can shield another electron from the full charge of the nucleus 3. penetration, which describes how one atomic orbital can overlap spatially with another, thus penetrating into a region that is close to the nucleus and is therefore is less shielded from nuclear charge

an aspirin tablet contains 325 mg of C9H8O4, how many of these molecules does it contain?

1.09X10^21

number of CO2 molecules in a sample of CO2 with a mass of 10.8g

1.48X10^23 CO2 molecules

how many CH2Cl2 molecules are there in 25.0 g of CH2Cl2

1.77X10^23

the lewis structure for N2has how many electrons?

10 (each N has 5 electrons, they share 3 electron pairs)

determine the mass of potassium in 35.5g of KBr

11.7g

formula mass of glucose, C6 H12 O6

180.16

the s sublevel has ____ orbital and can hold ____ electrons

1;2

most groups of the periodic table don't exhibit any definite trend in electron affinity. among the group _______metals, however, electron affinity becomes more positive as we move down the column (adding an electron becomes less exothermic)

1a

choose the correct electron configuration for Se

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4

electron configuration for bromine

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 or [Ar] 4s2 3d10 4p5

electron configuration for Mg

1s2 2s2 2p6 3s2 or [Ne]3s2

the p sublevel has ____ and can hold ____ electrons

3; 6

between 3s, 3p, and 3d which penetrates the most into inner orbitals and are the least shielded, and experience the greates effetive nuclear charge

3s; 3d electrons penetrate the least

in its compounds carbon always forms ____ bonds

4

formula mass of CO2

44.01 amu

is a 4s orbital or a 3s larger?

4s

calculate the mass of Cl in 1.00 kg CCl2F2

5.86X10^2

mass percent of Cl in CCl2F2

58.64%

the d sublevel has ____ orbitals and can hold _____ electrons

5; 10

formula mass/molar mass/atomic mass of Na2O

61.98 amu

mass percent of Cl in freon-112 (C2Cl4F2)

69.58%

the f sublevel has _____ orbitals and can hold _____ electrons

7; 14

which substance is an ionic compound a) SrI2 b) N204 c)He d)CCL4

A) SrI2

which are the larger atoms? N or Al

Al

write the electron configuration and orbital diagram for each ion and determine whether its diamagnetic or paramagnetic: Al3+

Al [Ne] 3s2 3p1 al3+ [Ne] 2s2 2p6 diamagnetic because there are no unpaired electrons

write the formula for the ionic compound between aluminum and oxygen

Al2O3 (2*-3) and (3*2-)+6

which element has a higher first ionization energy: As or Sb

As

arrange these atoms in order of increasing radius: Cs+, Ba2+, I-

Ba2+<Cs+<l-

zig zag line from ___ to ____ that divides metals and non metals

Boron, Astatine; also Ge and Sb

choose the larger atom or ion: Br- or Kr

Br-, has one fewer proton, resulting in a smaller pull on the electrons and therefore a larger radius

combustion of 30.42 g of a compound containing only carbon, hydrogen, and oxygen produces 35.21g CO2 and 14.42g H2O. what is the empirical formula of the compound?

C2H4O3

a compound is 52.14%C, 13.13%H, and 34.73% O by mass. what is the empirical formula for the compound?

C2H6O

a compound has the empirical formula CH2O and a formula mass of 120.10 amu. what is the molecular formula of the compound?

C4H8O4

what is the empirical formula of the compound with the molecular formula C10H8

C5H4

write the empirical formula of the molecular formula C4H8

CH2; divide subscripts by the greatest common factor

choose the larger atom or ion: Ca or Ca2+

Ca, has an argon core and 2 4s electrons and they are the outermost electrons and are shielded from nuclear charge by the core electrons. the Ca2+ lost its 4s electrons

write the formula for the ionic compound that forms between calcium and oxygen

CaO (2+ and 2-)

what is the correct formula for the compound that forms between calcium and sulfur

CaS

list the elements in the compound CF2CL2 in order of decreasing mass percent composition

Cl>F>C

cobalt(II) chloride hexahydrate

CoCL2*6H2O

write the electron configuration and orbital diagram for each ion and determine whether its diamagnetic or paramagnetic: Fe3+

Fe [Ar] 4s2 3d6 Fe3+ [Ar] 4s0 3d5 paramagnetic

which is the larger atom? C or Ge

Ge

list the 7 diatomic molecules:

H2, N2, O2, F2, Cl2, Br2, I2

hydrogen peroxide

H2O2

empirical and molecular formula for hydrogen peroxide:

HO; H2O2

choose the more metallic element: Ge or In

In

ionic compound for naming potassium and fluorine

KF

what is the formula for Manganese(IV) oxide

MnO2

which element has a higher first ionization energy: N or Si

N

which is the larger atom N or F?

N

ammonia

NH3

some main group metals such as ____ and _____ form more than one type of cation

Pb and Sn

name compund PCl5

Phosphorous pentachloride

which element has the higher first ionization energy: Al or S

S

write the electron configuration and orbital diagram for each ion and determine whether its diamagnetic or paramagnetic: S2-

S [Ne] 3s2 3p4 S2- [Ne] 3s2 3p6 diamagnetic

choose the more metallic element: P or Sb

Sb

choose the more metallic element: Sn or Te

Sn

arrange these elements in order of increasing first ionization energy: Cl, Sn, Si

Sn<Si<Cl

early demonstration of electron spin, involved the interaction of a beam of silver atoms with a magnetic field

Stern-Gerlach

the transition metals _____ and ______ form cations with the same charge in all of their compunds.

Zn and Ag

what is the electron configuration fro Fe2+?

[Ar] 4s0 3d6

whats the difference between ionic and molecular compounds?

a molecular compound is composed of covalently bonded molecules.

which set of 4 quantum numbers corresponds to an electron in a 4p orbital? a) n=4, l=1, m1=0, ms=1/2 b) n=4, l=3, m1=3, ms=-1/2 c) n=4, l=2, m1=0, ms=1/2 d) n=4, l=4, m1=3, ms=-1/2

a) n=4, l=1, m1=0, ms=1/2

the transfer of an electron from sodium to chlorine by itself is absorbing or giving away energy?

absorbing, endothermic

group 1a elements, have outer electron configuration that are one electron beyond a noble gas, in reactions have a 1+ charge

alkali metals

group 2a elements, 2 electrons beyond a noble gas, form a 2+ charge

alkaline earth

name compound AlCl3

aluminum chloride

moseley listed elements in order of _______ instead of atomic mass and resolved mendeleevs problem

atomic number

then number of electrons in an element is equal to its?

atomic number

a set of average bonding radii determined from measurements on a large number of elements and compounds, the radius of an atom when it is bonded to another atom and is always smaller than the van der waals radisu

atomic radius

the pattern of orbital filling where only 2 electrons of opposing sins are allowed in each orbital

aufbau principle

which species is diamagnetic? a) Cr2+ b) Zn c) Mn d) C

b) Zn

which statement is true about effective nuclear charge? a) effective nuclear charge decreases as we move to the right across a row in the periodic table b) effective nuclear charge increases as we move to the right across a row in the periodic table c) effective nuclear charge remains relatively constant as we move to the right across a row in the periodic table d) effective nuclear charge increases, then decreases, at regular intervals as we move to the right across a row in the periodic table

b) effective nuclear charge increases as we move to the right across a row in the periodic table

identify the correct trends in metallic character a) metallic character increases as we move to the right across a row in the periodic table and increases as we move down a column b) metallic character decreases as we move to the right across a row in the periodic table and increases as we move down a column c) metallic character decreases as we move to the right across a row in the periodic table and decreases as we move down a column. d) metallic character increases as we move to the right across a row in the periodic table and decreases as we move down a column

b) metallic character decreases as we move to the right across a row in the periodic table and increases as we move down a column

according to cuolombs law if the separation between two particles of the same charge is doubled, the potential energy a) twice as high as it was before the distance separation b)is one-half as high as it was before the separation c) does not change d) is one-fourth as high as it was before the separation

b)is one-half as high as it was before the separation

name BaCl2*6H2O

barium chloride hexahydrate

compound with only two elements

binary compound

a shared pair of electrons

bonding pair

name for BrO3^-

bromate

for which element is the gaining of an electron most exothermic? a) Li b) N c) F d) B

c) F

the ionization energies of an unknown third period element are shown here. identify the element IE1=786 Kj/mol; IE2=1580Kj/mol, IE3=3230 kj/mol, IE4=4360kj/mol a) Mg b) Al c) Si d) P

c) Si

which electron in S is most shielded from nuclear charge? a) an electron in the 1s orbital b) an electron in a 2p orbital c) an electron in a 3p orbital d) none of the above (all of these electrons are equally shielded from nuclear charge)

c) an electron in a 3p orbital

which atoms valence electrons experience the greatest effective nuclear charge? a. the valence electrons in Mg b. the valence electrons in Al c. the valence electrons in S

c. S Mg<Al<S

name the compound CaBr2

calcium bromide

name CaSO4*1/2H2O

calcium sulfate hemihydrate

which element has a higher first ionization energy: O or Cl

can't tell

which are the larger atoms? Al or Ge

cannot determine

choose the more metallic element: S or Br

cant tell

name CO2

carbon dioxide

when an unknown compound undergoes combustion or burning in the presence of pure oxygen

combustion analysis

CuSO4*5H2O

copper (II) sulfate pentahydrate

electrons in complete principal energy levels and those in complete d and f sublevels

core electrons

the difference between the two types of shielding:

core electrons efficiently shield electrons in the outermost principal energy level from nuclear charge, but outermost electrons do not efficiently shield one another from nuclear charge

when two atoms approach each other the electrons from one atom attach to the nucleus of another according to ______ law

coulumbs

according to ________ the attraction between a nucleus and an electron increases with increasing magnitude of nuclear charge. the higher the charge the more tightly it is held

coulumbs law

what is the charge of the ion most commonly formed by S? a) 2+ b) + c) - d) 2-

d) 2-

which element has the smallest radius? a) C b) Si c) Be d) F

d) F

which statement is true about electron shielding of nuclear charge? a) outermost electrons efficiently shield one another from nuclear charge b) core electrons efficiently shield one another from nuclear charge c) outermost electrons efficiently shield core electrons from nuclear charge d) core electrons efficiently shield outermost electrons from nuclear charge

d) core electrons efficiently shield outermost electrons from nuclear charge

first ionization energy ________ going down and ______ going across a row and effective nuclear charge _________. outermost electrons are further away

decrease, increase, increase

as we move to the right across a row or period in the periodic table metallic characteristics ____________. as we move down a column in the periodic table metallic character __________.

decrease; increases

since sodium is positive and chlorine ions are negative the potential energy increases or decreases?

decreases

when 3s,3p,and 3d orbitals have same energy

degenerate

2

di

when an atom or ion in which all electrons are paired is not attracted to an external magnetic field-it is instead slightly repelled-and we say that the atom or ions is_____

diamagnetic

is Zn2+ diamagnetic or paramagnetic?

diamagnetic because it loses its 4s electrons

the modern periodic table is credited to _______ he noticed that certain groups of elements had similiar properties. when he listed elements in order of increasing mass, these simliar properties recurred in a periodic pattern

dimitri mendeleev

name the compound P2I4

diphosphorus tetraiodide

how do you get an empirical formula from a molecular one?

divide the subscripts by the greatest common factor

for the lewis structure represent valence electrons of main group elements as....

dots surrounding the element

is a double bond or single bond stronger?

double

formula for effective nuclear charge

effective nuclear charge = actual nuclear charge - the charge shielded by other electrons

a measure of how easily an atom accepts an additional electron and is crucial to chemical bonding because bonding involves the transfer or sharing of electrons

electron affinity

the energy change associated with the gaining of an electron by the atom in the gaseous state; usually but not always negative, exothermic

electron affinity

formula that indicates the relative number of atoms in of each element in a compound

empirical formula

the orbitals within a principal level of multi-electron atom, in contrast are not degenerate their energy depends on the value of l. the lower the value of l within a principal quantum number the lower the _____ of the corresponding orbital

energy

t/f electrons generally occupy the highest energy orbitals

false, lowest

t/f ioinc compounds sometimes contain positive and negative ions

false; always

t/f a molecular compound can always be determined from its constituent elements

false; cannot because the same combination of elements may form several different molecular compounds

t/f ionization energy is always negative because removing an electron always takes energy

false; positive and endothermic

t/f in a covalent bond the atoms transfer electrons

false; share

basic unit of ionic compound, smallest electrically neutral collection of ions

formula unit

nonmetals lose or gain electrons when they undergo chemical changes?

gain

an electron in a 2p orbital has a less than or greater probability of being found closer to the nucleus that an electron in a 2s orbital? the 2s orbital is lower in energy but only when the 1s orbital is occupied, (when the 1s orbital is empty, the 2s and 2p orbitals are degenerate

greater

as the outer electron undergoes penetration into the region occupied by inner electrons, it experiences a less than or greater nuclear charge and therefore a lower energy? according to coulumbs law

greater

for main-group elements electron affinity usually becomes more negative as we move to the right. the ______ have the most negative electron affinities. however 5a elements do not follow the trend the repulsion between 2 electrons occupying the same orbital causes the electron affinity to be more positive than that for elements in the previous column

halogens

group 7a elements, one electron short of noble gas, 1- charge

halogens

always has two paired dots , duet because n=1 quantum level fills with only 2 electrons

helium

except for ______ the number of valence electrons for any main-group element is equal to its lettered group number

helium

1/2

hemi

7

hepta

6

hexa

when filling degenerate orbitals, electrons fill them singly first, with parallel spins

hunds rule

how is a compound different form a mixture of elements?

in a compound elements combine in fixed definite proportions ; in a mixture, elements can mix in any properties whatsoever

the density of elements tends to (increase/decrease) as we move down a column of the periodic table

increase

atomic radii _____ as move down a column, and ______ as we move to the right

increase, decrease

atomic radii ________ going down and ______ going across a row and effective nuclear charge _________. size of outermost occupied orbital increases

increase, decrease, increase

metallic character ________ going down and ______ going across a row and effective nuclear charge _________. ionization energy ______

increase, decrease, increase, decreases

the magnitude of the interaction between charged particles ______ as the charges of the particles ______. consequently an electron with a charge of 1- is more strongly attracted to a nucleus with a charge of 2+ than it is to a nucleus with a charge of 1+

increase; increase

as move down the periodic table the highest principal quantum number of valence electrons_______. consequently the valence electrons occupy larger orbitals, resulting in larger atoms

increases

as we move down the column in the periodic table the radius if an atom(increases/decreases)

increases

as we move down a column in the periodic table, the principle quantum number of the electrons in the outermost principal energy level ______, resulting in ______ orbitals and therefore _______ atomic radii

increases, larger, larger

as we move to the right across a row in the periodic table the effective nuclear charge experienced by the electrons in the outermost principal energy level ______, resulting in a stronger attraction between the outermost electrons and the nucleus, and _____ atomic radii

increases, smaller

first ionization energy ______ going to the right and ______ going down

increases; decreases

name for IO2

iodate

the formula of an ______ compund reflects the smallest whole number ratio of ions

ionci compound

how are ionic bonds different from covalent

ionic bonds are nondirectional and hold together an array of atoms

the energy required to move an electron from the atom or ion in the gaseous state.

ionization energy

anions are much (smaller/larger) than their corresponding neutral atoms

larger

the energy associated with the formation of a crystalline lattice of the compound from the gaseous ions

lattice energy

name the compound Pb(C2H3O2)2

lead (II) acetate

name the compound PbCl4

lead(IV) chloride

an orbital that penetrates into the region occupied by core electrons is _____ shielded from nuclear charge than an orbital that does not penetrate and therefore has a ______ energy

less, lower

a common bonding theory that explains why some combinations of atoms are stable and predicts the shape of th emolecules

lewis model

______________ predicts whether a particular set of atoms will form a stable molecule and what the molecule might look like

lewis structure

the potential energy associated with ____ charges is positive but decreases as the particles get farther apart. since systems tend toward lower potential energy like charges that are close together have high potential energy and tend to move away from each other toward lower potential energy. these charges repel each other

like charges

name the compound Li2Cr2O7

lithium dichromate

a pair only associated with one atom and therefore not involved in bonding

lone pair or nonbonding electrons

metals _____ electrons but nonmetals______

lose; gain

metal gains or loses electrons when it undergoes a chemical change?

loses, in order to obtain a noble gas

when a quantum level is completely full, the overall potential energy of the electrons that occupy that level is particularly high/low?

low

when an outer principal quantum level is full the overall potential energy of the electrons is low or high

low

according to coulumbs lawchemical bonds form to lower/raise the potential energy of the charged particles that compose atoms

lower

the 2s orbital because it experiences more of the nuclear charge due to its greater penetration is lower or greater in energy than the 2p orbital?

lower

the 4s orbital is generally _____ in energy than the 3d orbital

lower

when two electrons occupy separate orbitals of equal energy, the repulsive interaction between them is ______ than when they occupy the same orbital because the electrons are spread out over a large region of space

lower

the most stable arrangement is the one with the lowest or highest potential energy?

lowest, noble gases

name MgSO4*7H2O

magnesium sulfate heptahydrate

form for solving an equation where asked to find the mass of an element present in a given mass of a compund

mass compound--moles compound---moles element----mass element

one way to express how much of an element is in a given compound

mass percent composition

an ionic bond is between ______ and __________

metal and nonmetal

ionic compounds are usually composed of __________ and ________

metals and nonmetals

covalent bonds form _______ compounds

molecular

who has the lower melting and boiling points molecular or ionic compounds??

molecular compounds because... the covalent bonds between atoms of a molecule are much stronger than the interactions between molecules. to bring a molecular substance to a boil only the relatively weak intermolecular forces have to be overcome, so molecular compounds often have low boiling points

formula that indicates the actual number of atoms of each element in a molecule of a compound

molecular formula

1

mono

valence electrons are held more or less loosely than the core electrons?

more

in a chemical formula does the more metallic or less metallic atom go first?

more metallic, more positively charged. 2:1, 1:1, 1:4

an electron with a higher charge is held(more/less tightly) and has (higher/lower) potential energy according to coulumb's law, making it (more/less) difficult to remove, and making the atom (smaller/bigger)

more, lower, more, smaller

molecular formula = empirical formula X _____

n

the principal quantum number symbol

n

what are the 4 quantum numbers for each of the two electrons in a 4s orbital?

n=4, l=0, ml=0, ms=+12 ??

naming binary ionic compounds containing a metal that forms only one type of cation:

name of the cation metal + base name of the anion (nonmetal) -ide

name compound NCl3

nitrogen trichloride

name compund NI3

nitrogen triiodide

electron affinity ________ going down and ______ going across a row and effective nuclear charge _________.

no definite trend, decrease, increase

can solid ions move?

no only liquid

pauli exclusion principle:

no two electrons in an atom can have the same four quantum numbers. implies that each orbital can have a maximum of only two electrons with opposing spins

part of the periodic table that has full outer quantum levels and are particularly stable and unreactive

noble gases

according to ________ one way to define atomic radii is to consider the distance between nonbonding atoms that are in direct contact, determined by the solids density is twice the radius of the element. represents the radius of an atom when it is not bonded to another atom

nonbonding atomic radius, or Van der Waals radius

covalent bond is between two or more _____ and _______

nonmetals and nonmetals

systems with high potential energy tend to change in ways that lower their potential energy. systems with low potential energy tend ___________ and are stable

not to change

8

octa

john newlands organized elements into _____ in an analogy to musical notes were every 8th property elements were similiar

octaves

rule that says stable configurations is usually 8 electrons in the outermost shell

octet rule

with each row the highest principal quantum number increases by ____

one

the van der waals radius of an atom:

one-half the distance between adjacent nuclei in the atomic solid

bonding atomic radius/covalent radius for nonmetals:

one-half the distance between two of the atoms bonded together

bonding atomic radius/covalent radius for metals:

one-half the distance between two of the atoms next to each other in a crystal of the metal

an unpaired electron that has spin

paramagnetic

no two electrons in one atom can have the same four quantum numbers

pauli exclusion principle

5

penta

an ion composed of two or more atoms example: hypochlorite

polyatomic ion

any one electron in a multi-electron atom experiences both the __________ charge of the nucleus and ________ charge of other electrons

positive, negative

how to name binary molecular compounds:

prefix+name of more metallic element (generally the one with the smallest group number first, if 2 elements lie in the same group use element with greatest row number first)+prefix+base name of second element + -ide

_______ theory explains the elctronic structure of atoms, this in turn determines the properties of atoms

quantum mechanical theory

theory that explains the electronic structure of atoms, which in turn determines their properties, since family has similar properties the electronic structure should have similarities as well

quantum-mechanical theory

as you move down each column, the number of electrons in the outermost principal energy level (highest n value) ....

remains the same

when dealing with ions for main group cations, we remove the required number of electrons by?

removing in the reverse order of filling F-= 1s2 2s2 2p6

choose the larger atom or ion: S or S2-

s2- , it has same number of protons but 2 more electrons

for a given value of n, the level of energy within orbitals:

s<p<d<f

the repulsion of one electron by other electrons

screening/shielding

the inner electrons in the effective nuclear charge _____ outer electrons from the full nuclear charge

shield

the first atempt to organize these elements according to ______ was made by dobereiner who grouped the elements into triads(3 elements with similiar properties)

similiarities in their properties

cations are much (smaller/larger) than their corresponding neutral atoms

smaller

name Na2O

sodium oxide

coulombs law:

states that the potential energy of two charged particles depends on their charges and on their separation. the magnitude of the potential energy depends inversely on the separation between the charged particles.

instead of decreasing in size the radii of transition elements _______________ across each row

stays roughly the same

name the compound SrI2

strontium iodide

formula that uses lines to represent covalent bonds and shows how atoms in a molecule are connected or bonded to each other

structural formula

________ determines properties

structure

4

tetra

name compound P4 S10

tetraphosphorous decasulfide

what is formula mass

the formula mass is the sum of all the atomic masses. (number of atoms in 1st elementXitsatomic mass) + .....

naming binary ionic compounds containing a metal that forms more than one type of cation:

the name of the cation is folllowed by a roman numeral in parantheses, which indicates the charge of the metal in that particular compound. name + (roman numerals) + base name of anion + -ide

aufbau principle

the pattern of orbital filling where only 2 electrons of opposing sins are allowed in each orbital

covalent bonds are highly directional. the attraction between two covalently bonded atoms is due to....

the sharing of one or more electron pairs in the space between them, thus each bond links just one specific pair of atoms

the approximate bond length of any two covalently bonded atoms is the sum of______

their atomic radii

according to cuolombs law what happens to the potential energy of two oppositely charged particles as they get closer together?

their potential energy decreases

what are main group-elements:

those in the 2 far-left columns (groups 1A and 2A) and the 6 far-right columns (groups 3A-8A)

_______ metals usually have different charges for different compunds

transition metals

3

tri

t/f an ionic compound can always be determined from its constiuent elements

true

t/f an ionic solids lattice structure is not directional meaning forces are equal all around, requires heat to overcome it

true

t/f as the electron penetrates the electron cloud of the 1s electrons, it begins to experience the 3+ charge of the nucleus more fully because the third electron is less shielded by the intervening electrons

true

t/f atomic number increases from left to right and elements with similiar properties are aligned in columns

true

t/f chemical formulas give us a relationship between the amount (in moles) of substances, not between the masses (in grams) of them

true

t/f electrons occupy orbitals so as to minimize the energy of the atom, therefore low-energy orbitals fill before higher-energy orbitals

true

t/f forming cations always requires energy and forming anions sometimes does; the energy cost of forming one with a noble gas configuration is less than the energy payback when forming chemical bonds

true

t/f in a chemical formula the sum of the positive charges must equal the sum of the negative charges

true

t/f ionic compunds must be charge neutral

true

t/f the chemical properties of elements are largely determined by the number of valence electrons the elements contain

true

t/f the density of aluminum metal is low because the density of an aluminum atom is low

true

t/f the forming of an ionic compound gives off energy as heat, exothermic

true

t/f the mass of each successive atom increases even more than its volume does, resulting in a higher density

true

t/f the molecular formula is always a whole-number multiple of the empirical formula

true

t/f to represent ionic bonding we move electron dots from the lewis symbol of the nonmetal , so the metal becomes a sation and the nonmetal becomes an anion

true

t/f transition metals tend to lose electrons in their chemical changes, but they do not generally attain noble gas electron configurations

true

t/f when 2 or more elements combine to form a compound an entirely new substance results

true

chemical bonding involves the transfer or sharing of valence electrons between ______ or more atoms

two

molecular compounds are compose of.....

two or more nonmetals

the potential energy associated with the interaction of _____ charges is negative and becomes more negative as the particles get closer together. since systems tend toward lower potential energy, these charges therefore attract to one another

unlike charges

for main group elements theyre the electrons in the outermost principal energy level. for transition elements also count outermost as d, electrons held the most loosely

valence electrons

lewis structure:

valence electrons are represented as dots and draw lewis electron dot structure for simple lewis structures to depict molecules

when dealing with ions, for transition metal cations, how are the required number of electrons removed?

we remove the electrons in the highest n-value orbital first, even if this does not correspond to the reverse order of filling V2+ = [Ar] 4s0 3d3

hund's rule:

when filling degenerate orbitals, electrons fill them singly first, with parallel spins

periodic law as defined by mendeleev

when the elements are arranged in order of increasing mass, certain sets of properties recurr periodically.

is hydrogen a diatomic element?

yes