bonding all notes

who organized periodic table by increasing the atomic number

mendeleev

elements in the same group have similar

properties

elements in the same period have the same number of

energy levels

what is the only way the radius of an atom can be found

by measuring the distance between the nuclei of two touching atoms, and then halving that distance

½ of the distance between the nuclei of two like atoms

atomic radius

atomic size will decrease /increase as you move down a group due to a greater number of occupied energy levels

group trend (down) increase

atomic size will increase/ decrease from left to right

period trend (across) decrease

as distance increases between two charged particles, attraction gets

weaker

the elements have the same number of occupied energy levels, but a greater number of __________ which ________ the electrons __________ ___________ toward the ____________

protons; pull; more; strongly; nucleus

the period trend is less pronounced for periods further down the P.T. due to the _____________ ________

shielding effect

shielding effect: the inner electrons _________ the attraction from the nucleus

“shield” or block

shielding effect: there is still a decrease in size for _______ periods, but it is less significant

lower

atomic size (increases/decrease) as you move to the right and (increases/ decreases) as you move down

decreases; increases

as you move from the top to the bottom on a periodic table, the size of the atom will

increase

why does the size of an atom increase as you move down on the periodic table

because it occupies one more energy level each time it moves down

as you move from left to right across a period on the periodic table the size of the atom will

decrease

why does the size of the atom decrease as you move from the left to the right on the periodic table

because it has one more proton in its nucleus than the last one

within a period the elements will have the same number of

occupied energy levels

the ___________ effect is caused by the inner electrons interfering with the attraction of outer electrons for the proton in the nucleus

shielding

because of the shielding effect, electrons which are further from the nucleus are ______ attracted to the nucleus

less

the decrease in atomic size as you move from left to right across the periodic table becomes less pronounced as you move _________ the periodic table

down

atoms that have gained or lost an electron

ions

eight electrons in the outer shell (filled outer energy level) is the most stable configuration for an atom

noble gas configuration

atoms that only have a partially filled outer shell tend to _______________________ electrons trying to reach a more stable noble gas configuration

lose or gain electrons

the outer shell and electrons are called the _______________ and ______________________

valence shell and valence electrons

atoms that have lost an electron and now have a positive charge

cations

(non) metals tend to form cations

metals

have weaker pull on electrons, and less valence electrons, so easy for them to lose electrons to be stable

metals

the amount of energy required to remove an electron from a gaseous atom

ionization energy (I.E.)

the I.E. depends on

1- distance between the electron and nucleus

2- nuclear charge (number of protons)

closer to nucleus is more or less tightly held

more

the stronger the connection (electron with nucleus relationship), the harder/ easier to pull away the electron

harder

I.E. decreases/ increases as you go down a group due to a greater number of energy levels

group trend (down) decreases

closer to nucleus = a higher I.E. which results in it being more/ less difficult to remove an electron

more

farther to nucleus = a lower I.E. which results in it being more/ less difficult to remove an electron

less

I.E. increases/ decreases as you move across a period due to an increased nuclear charge

period trend (across) increases

electrons are held more tightly because of more protons therefore

more I.E. is required to remove an electron

2nd and 3rd electrons always require more energy to remove because they are attracted to a

positive ion than to a neutral atom

1 I.E. = energy required to remove ____ electron

2 I.E. = energy required to remove ____ electron

1;2

there is a very large increase of ionization energy whenever an electron is removed from an atom/ ion that is

isoelectronic with a noble gas

going down the periodic table, ionization energy ________

decreases

going to the right on a periodic table, the ionization energy _________

increases

atoms that gained an electron

anions

(non) metals tend to form anions

nonmetals

the energy change that occurs when an electron is acquired by a neutral atom (measure of how easy it is for an atom to gain e-)

electron affinity

group trend (down) electrons are easier/ harder to add as you move down a group

harder

as you move down a group, electrons are further/ closer to/ from the nucleus therefore, the ______________________/ attraction for more electrons is weaker/ stronger

further; from; nuclear charge; weaker

period trend (right) electron affinities become greater/ lesser as you move from left to right across a period

this is because there is an _______________________________ across a period which attracts new electrons more strongly/ weakly

greater

increase in nuclear charge; strongly

as you move down electron affinity is easier/ harder to gain

harder

as you move left to right electron affinity is easier/ harder to gain

easier

when electrons are lost, element gets bigger/ smaller

smaller

when electrons are gained, electrons gets bigger/ smaller

bigger

more protons equals less/ more atomic radius

less (remember more protons equals a smaller atom)

the tendency for an element to attract electrons when chemically combined with another element

electronegativity

does electronegativity increase or decrease as you go down a group

decrease

why does electronegativity decrease going down a group

electrons are less attracted as you go down a group

does e.n. increase or decrease as you go to the right

increase

why does e.n. increase as you go to the right

electrons are more attracted to the nucleus due to increased nuclear charge

why do atomic bonds form

to decrease potential energy and increase stability (both possible through filling valence shell)

electrons are shared between 2 atoms in a molecule or polyatomic bond

covalent bonding

electrons are transferred

ionic bonding

how are positively and negatively charged ions held together

electrostatic forces

un unequal attraction for shared electrons creating partially charged poles- asymmetrical electron density

polar covalent

electrons are shared equally creating symmetrical electron density

non polar covalent

in ionic bonds, the higher electronegative atom forms an

anion, it gained electrons

in ionic bonds, the lower electronegative atom forms a

cation, it lost electrons

electronegativity trend: as you go up across and down it increases/ decreases

increases

what is the electronegativity in nonpolar

0-0.5; the least it can be

what is the electronegativity in polar covalent

>0.5 but less than 1.67; middle numbers

what is the electronegativity in ionic

>1.67; highest numbers

electrons are shared equally, symmetrical electron density, usually between identical atoms

nonpolar covalent bonds

electrons shared unequally, asymmetrical electron density, results in partial charges

polar covalent bond

electrons are transferred, ions are formed, electrostatic attraction between cations and anions

ionic bond

sharing of electrons (non-metal and non-metal)

covalent

transfer of electrons (metal and non-metal)

ionic

what are bonds between the same type of metal

metallic bonds

atoms of the same metal join by the

overlap of the outer energy level

do metals or nonmetals have high melting/ boiling points, are malleable, are ductile, lusterous, good conductors

metals

what compound is composed of positive and negative ions

ionic

nonmetal has higher/ lower electronegativity than metal

higher

valence electrons are transferred from the metal/ non-metal to the metal/ non-metal

metal; non-metal

there is an electrostatic attraction between ___ and _____ ions

+ and - ions

most ionic compounds exist as a

crystalline solid

three dimensional network of positive and negative ions mutually attracted to one another

crystal lattice

compounds lattice energy indicates amount ________ of ionic bonds

strength

the chemical formula for an ionic compound

formula unit

what compounds have high melting/ boiling points, solid at room temp, hard but brittle and rigid, conductors of electricity in molten or dissolved state

ionic compounds; this is because ionic bonds are very strong chemical bonds

use two dots on same side in electron dot diagram for

helium