Big Big Big chem test

Are atoms more likely to be found as independent particles, or combinations of atoms?

Combinations of Atoms

a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together

Chemical Bond

Atoms form \______________ by gaining, losing, or sharing electrons.

Compounds

A measure of the ability of an atom in a chemical compound to attract electrons in a chemical bond

Electronegativity

3\.3 to 1.7, %100-50

Ionic

Unequal sharing of electrons, 1.7 to .3, %50-5

Polar Covalent

Equal sharing of electrons, .3 to 0, %5-0

Nonpolar Covalent

δ-, for the element in a compound with a greater electronegativity in a polar bond

Slightly Negative Symbol

δ+, for the element in a compound with a smaller electronegativity in a polar bond

Slightly Positive Symbol

A chemical compound whose simplest units are molecules

Molecular Compounds

A molecule is still neutral when polar because the \______________ positives and negatives cancel each other out

Slight

Atoms tend to form bonds to follow the \____________ rule

Octet

atoms gain, lose, or share valence electrons to achieve noble gas configuration

Octet Rule

Hydrogen is an exception to the octet rule because hydrogen forms bonds when it is surrounded by only \________ electrons

Two

BF3 is an exception because boron has __ valence electrons an receives an electron from each of the three fluorine atoms for a total of __ electrons

3, 6

what are the Expanded Octets

PCl5 and SF6

an electron configuration in which only the valence electrons of an atom of a particular element are shown, indicated by dots placed around the element's symbol

Electron Dot Notation

Electron dot notations can represent \_____________

Compounds

A pair of valance electrons that is not shared between atoms

Lone Paired Electrons

Formulas in which dot-pairs or dashes between two atomic symbols represent electron pairs in covalent bonds, and dots adjacent to only one atomic symbol represent unshared electrons, with no unpaired electrons

Lewis Structures

atoms gain, lose, or share electrons to achieve what

greater stability, noble gas configuration, and an octet in the outer energy level

what is a neutral group of atoms held together by covalent bonds

molecule

the types and numbers of atoms joined in a single molecule of a molecular compound is termed what

molecular formula

ionic bonds form as a result of the attraction between what

anions and cations

you can classify a bond by calculating

the difference in the atoms’ electronegativities

the greater the difference in electronegativity between two atoms, the great the %\_____

ionic

if two covalently bonded atoms are identical, the bond is

non-polar covalent

in a molecule of Hal, which atom would be slightly positive

hydrogen

which type of bond would be described as unequal sharing of electron pairs between atoms

polar covalent

what is composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal

Ionic compound

what is different between ionic compounds and molecular compound

an ionic compound is not composed of independent, nuetral units that cam be isolated and examined, while molecular compounds are

which has a stronger attraction between formula units and molecules and why

formula units’ attractions are stronger than molecules’ due to the molecule's’ hydrogen bonds

between ions and molecules which are solid and gas at room temp

ions are solids and molecules are gases at room temp

between ionic and molecular compounds which melt at low temps and which at high temps

molecular compounds melt at low temps while ionic compounds have higher melting points

when can ionic compounds conduct electricity

when they are in the molten state because they can move freely to carry electrical currents

what is a polyatomic ion

it is a charged group of covalently bonded atoms why

why are ionic compounds hard but brittle

forces in ions crystals make it difficult for one layer to move relative to another. Where one layer moves, the repulsive forces make the layers part completely, causing them to be brittle

do polyatomic bond covalently or ionically

ionically

what is the therm for the force that holds two ions together in an ionic bond

electrostatic force

what is the smallest of the ions in an ionic compound from which its chemical formula can be written

formula unit

what is unequal sharing of electron pairs which results in uneven distribution of charge

polar covalent bond