Science November 2017 Atoms and Bonding
Terms in this set (87)
The electrons in an atom that have the highest energy.
The electrons of an atom are found in different...
Certain number of
Each atom of an element has a...valence electrons.
Eight, Hydrogen and Helium-2
What is the number of valence electrons that most atoms want to get to? Exceptions?
Electron dot diagram
Includes the symbol for the element surrounded by dots;each dot stands for a valence electron.
Transferred, shared between atoms
When atoms bond, valence electrons can be ___ or ___ ___ ___.
The force of attraction that holds atoms together as a result of the rearrangement of electrons between them.
Left to right, period
The number of valence electrons increases from...across a ___.
The elements within a group (except period 1) always have the same number of what?
How many valence electrons do the element in group 2 have?
How many valence electrons do the element in group 17 have?
They are stable with 8 electrons
Why are noble gases unlikely to gain, share, or lose electrons?
Metals react by ___ their valence electrons.
The ease with which its atoms lose valence electrons
Generally, the reactivity of a metal depends on...
Nonmetals react by ___ or ___ electrons.
A gain of 1 more electron gives the ___ 8 valence electrons.
Losing or sharing
Metalloids react by ___ or ___ electrons.
Hydrogen is considered to be a...
Electron, 2 valence electrons
Hydrogen shares its...when forming compounds with other nonmetals to get...
An atom or a group of atoms that has an electric charge.
Loses positive gains negative
When a neutral atom loses a valence electron, it ___ a negative charge. It becomes a ___ ion. When a neutral atom gains an electron, it ___ a negative charge. It becomes a ___ ion.
Some ions are made of...
Ions that are made of more than one atom.
Valence electrons are transferred, makes them more stable
When atoms that easily lose electrons react with atoms that easily gain electrons what happens? What does this do to both atoms?
The attraction between two oppositely charged ions;usually a metal and a nonmetal
Ionic compound, equals
The result of an ionic bond;made of positive and negative ions;the total positive charge of all the positive ion ___ the total negative charge of all the negative ions.
A group of symbols that shows the ratio of elements in a compound.
Balance the charges on the ions
When ionic compounds form, the ions combine to...
Tell the ratio of elements in a compound.
Positive negative subscripts balance the charges
To write the formula for an ionic compound, write the symbol of the ___ ion and then the symbol of the ___ ion. Add the ___ that are needed to...
For an ionic compound, the name of the ___ ion comes first, followed by the name of the ___.
The positive ion in an ionic compound is usually a ___, but do polyatomic ions exist?
If the negative ion in an ionic compound is a single element, what does the end of its name change to?
-ate or -ite
If the negative ion in an ionic compound is polyatomic, what does the end of its name change to?
Hard, brittle, crystals, high
In general, ionic compounds form ___, ___ ___ that have ___ melting points.
Dissolved in water or melted
Ionic compounds conduct electric current when they are...
Repeating patterns of ions
Ionic compounds form solids by building up...
An orderly, 3D arrangement formed by ions.
True or False:The pattern formed by ions in a crystal are different depending on how big they are.
The strength of their ionic bonds and the attractions among ions
The hardness and brittleness of crystals are due to...
They must break apart
What must happen to the ions in a crystal for an ionic compound to melt?
Yes, the great attractions between the ions
Does it take a lot of energy to melt ionic compounds? Why?
The flow of charged particles.
The ions are free to move about
Why can ionic crystals conduct electricity once they dissolve?
The ions are tightly bound and cannot move
Why can't ionic crystals conduct current well?
The chemical bond formed when two atoms share electrons;usually forms between nonmetal atoms.
The attractions between the shared electrons and each atom's protons
What holds the atoms together in a covalent bond?
A neutral group of more than two atoms held together by covalent bonds.
A chemical bond formed when atoms share two pairs of electrons.
A chemical bond formed when atoms share three pairs of electrons.
A compound that is made up of molecules;covalently bonded atoms into molecules into this.
Ionic compounds are made of ___ and do not form ___.
Do not conduct
Unlike ionic compounds, molecular compounds usually...electric current when melted or dissolved in water.
Compared to ionic compounds, molecular compounds generally have ___ melting and boiling points.
They do not contain charged particles that are able to move
Why can't molecular compounds conduct current?
True or False:As liquids, molecular compounds are good conductors.
The forces that hold molecular solids together are ___ ___ than the forces that hold ionic compounds together.
Compared with an ionic solid, ___ heat must be used to separate the molecules of a molecular solid and liquidate it.
What results from atoms of some elements pulling more strongly on the shared electrons of a covalent bond?
Covalently bonded atoms to have slight electric charges
Unequal sharing results in...
A covalent bond in which electrons are shared equally
A covalent bond in which electrons are shared unequally
In polar bonds, the atom with a ___ pull gains a slightly negative charge. The atom with a ___ gains a slightly positive charge.
Negatively charged end and a positively charged end, no
A molecule is polar if it has a...but are all molecules with polar bonds polar overall?
In opposite directions, nonpolar
In CO2 the two Os pull...The pulls make it so the molecule is ___.
In H2O the O pulls...The pull makes the molecule___.
In H2O, does
A)the oxygen side have the negative charge or
B)the hydrogen side have the negative charge?
Van der Waals forces
Polar molecules are connected to each other by weak attractions between their slight negative and positive charges called...
The differences in attractions between the molecules
The properties of polar and nonpolar compounds are different because of what?
The attractions between polar molecules require ___ energy to overcome than the attractions between nonpolar molecules.
By the structure of and the bonding among the atoms
By what can the properties of solid metals can be explained?
They do not hold onto their valence electrons very strongly
Why do metal atoms use electrons easily?
Closely packed, positively charged metal ions
A metal crystal is composed of ___ ___, ___ ___ ___ ___. The valence electrons drift among the atoms.
Hold metal ions in crystals;an attraction between a positive metal ion and the electrons surrounding it.
Metallic bonding and the behavior of valence electrons
What two things explain many of the common physical properties of metals?
Luster, high malleability, ductility, and electrical and thermal conductivity
Properties of metals include what five things?
Polished metals have a shiny and reflective luster called...
Its valence electrons, they absorb and re-emit it
What gives a metal its luster? What does that/those do with the light that strikes them?
Positive metal ions, loose electrons around them, metal ions, ions, change position, ions, electrons, metal ions, bonds between
Metals are ductile and malleable because the ___ ___ ___ are attracted to the ___ ___ ___ ___ rather than other ___ ___. These ___ can be made to ___ ___, but the ___ ___ the ___ and the ___ keep the ___ ___ from breaking apart from one another.
The transfer of thermal energy from warmer matter to cooler matter.
Their valence electrons are free to move
Why do metals conduct heat easily?
Conduct an electric current
Charged particles that are free to move can...
The valence electrons can move freely between the atoms
Why can metals conduct electricity?
A mixture made of two or more elements, at least one of which is a metal.
Stronger and less reactive
Alloys are generally...than the pure metals from which they are made.
Harder, beauty and shine
Gold alloys are much ___ than pure gold, but still retain its ___ ___ ___.
Stronger, resist rust much better
Iron alloys are much ___ and...