Smallest particle of an element or a compound that retains the characteristics of the original substance
What kind of molecule is water?
Triatomic molecule. Two hydrogen atoms,and one oxygen atom must combine to from substance water with its characteristic properites.
What happens to valence electrons when atoms combine forming molecules?
Valence electrons and outer energy level of each atom shift
What happens after shifting of valence electrons and outer energy level of each atom shifting?
This results in completion of outer energy level of each atom.
How can you achieve a stable from of electrons?
The gain or loss of electrons, and sharing of pairs of electrons
What happens to energy during chemical bond?
When bond is formed, Energy is released, and when bond is broken, energy is absorbed.
What is the distinguishing factor in the stable configurations ?
The arrangement of two s electrons, and six p electrons in the valence energy level in five of the six atoms
Having a single s valence energy level which is filled with two electrons making He a very stable atom
How many electrons do non-noble gases have, and how reactive are they?
Noble gases have one to seven electrons in their outer energy levels. These elements are very reactive to varying degress.
What happens to electrons when they react to form chemical bonds?
Their electrons usually shift, and stable ocetets form.
What happens to atoms during bond formation?
Atoms usually attain stable electron structure of one of the noble gases
What happens to electrons when there is increasing electronegativity of more then 1.7?
Atoms ten d to blorrow electrons to fill energy level, and other atom will also lend electrons until it also has a complete energy level
What do these ions form?
They are arranged into a crystal lattice or giant ion-molecule containing many such ions.
What kind of melting points do ionic solids have?
They tend to have high melting points. They won't conduct current of electricity until they're in the molten state.
What happens when the electronegtavity between two or more atoms is 0 o very small (not greater than about 0.4)?
Atoms tend to share the valence electrons in their respective outer energy levels
What boliling points and tmpertures are covalents compounds?
Low boliling point, and solids melt at relatively low temperature. They don't conduct electric currents
What's the electronegtavity difference between covalenet bonds?
0.4-1.6. There won't be equal sharing of electrons. The s
What happens to electrons being shared between 0.4-1.6?
There wouldn't be equal sharing of electrons between atoms involved. The shared electrons will be more strongly attracted to the atom of greater electronegativity.
What happens to the plarity or degree of a covalent bond when it's difference increases above 0.4?
The ionic character increases. 1.7 or more, the bond has more than 50% ionic chracter
Why is it that an electron pair in a bond is shown close with more electronegative atom?
When these nonsymmetrical polar bonds are placed around a central atom, the overall molecule is polar.
Polar moleculs reffered to this b/c two distinct ends from a charge perspective. Unequal sharing.
What happens to most valence electrons in metals ?
They detach and migrate in a "sea" of free electrons
How much attractive force does a metal atom have?
It varies with the nuclear positive charge of the metal atoms, and the number of electrons in this electron sea
Both are reflected in the amount of heat required to vaporize the metal
What are metals melting points, strength and and electricity?
They show great strength and are good conductors of electricity.
poloar covalent bonding that unsymmetrical distribution of eletronic charges leads to positive and negative charges in molecules
What happens to dipoles in polar molecular substances?
They line up, so positive pole of one molecule attracts negative pole of another.
Compare the attractive forces between ionsin ionic crystals, and dipole-dipole attraction?
There less then the full charges charges
why does a molecule/atom that's usually nonpolar sometimes become polar
Constant motion of its electrons causes uneven charge distibutions
How is London's dispersion forces like?
weakest of all electrical forces of most dipole interactions, and weakest electrical forces
What does London's dispersion force prove about water and hydrogen?
nonpolar substances like these, noble gases and halogens condense to iliquid, and liquids turn into solid, when the temeprature is lowered sufficiently
How are london dispersion forces compounds like?
They have soft crystals, easily deformed, and vaporize easily
How are the london dispersion forces intermolecular forces, melting points, and evaporation like?
b/c of low intermolecular forces, melting points are low, evaporation takes place easily,
dipole-dipole attraction.proton or hydrogen nucleus- high concentration of positive charge.
What happens when a hydrogen atom is bonded to a highly electronegative atom?
It's positive charge will have an attraction for neighboring electron pairs.
How effective is hydorgen bonding binding molecules when it's more polar?
More effective in binding molecules into a larger unit
What does hydrogen bonding explain about vapor pressure, vaporization, melting points?
They say it has low vapor pressures, high vaporization, high melting points.
What has to happen to molecules in order for them to be seperated?
Molecules must be seperated. Energy must epend to break hydrogen bonds, then break down clusters of molecules into separate molecules
Ocetet structure (2 definations)
outer energy level resembling noble gas configuration of eight electrons- must share two or three pairs of electrons
What the correlation between electron density between nuclei and attractive force between nuclei and shared electrons?
The greater electron density, the greater attractive force
What happens to the double and triple bonds when strong bonds tend to pull atoms closer together?
They have smaller interatomic distances and greater bond strengths
Why is it sometimes you can't represent bonding structure of a molecule through Lewis dot structure or the line drawing?How is this then represented?
Because data about the bonding distance and bond strength are between possible drawing configurations and really indicate hybrid condition. They are represented through arrows.