Science 9th test notes
a structural symbol that represents the arrangements of atoms and the bonds between them within a molecule is call an____
Lewis dot structure
An element's symbol surrounded by dots that represent its valence electrons is called _____________________.
Lewis structure or electron dot notation
an unbonded atoms ability to attract and hold electrons is its___
electron affinity
one of the most effective models for describing the effective electron transfers that occur in an ionic compound is_____
electron dot notation
Metal elements typically form covalent bonds with other metals.
false
Most atoms share, gain, or lose valence electrons in order to attain six electrons in their highest energy level when they bond.
false
Most molecules are linear.
false
The bond between Na+ and Cl- in NaCl is an example of a purely ionic bond.
false
A given covalent bond can exist between only two atoms.
true
An atom's chemical instability is mainly due to an unfilled valence energy level.
true
An ionic bond forms between oppositely charged ions
true
An ionic compound's crystal lattice consists of a repeating pattern of positive and negative ions.
true
Bonding pairs of electrons spend most of their time between covalently bonded atoms.
true
Both bond type and bond strength are determined mainly by electronegativity difference.
true
Covalent bonds are most common between nonmetal elements.
true
Covalent bonds form when atoms share electrons.
true
Current flows in an electrolyte solution because anions flow toward the positive electrode and cations flow toward the negative electrode.
true
Diatomic oxygen contains two bonding pairs of electrons.
true
Electronegativity is one measure of the ability of an atom to attract electrons.
true
Electrons shared in covalent bonds are not necessarily equally shared.
true
Ionic bonds are generally much stronger than covalent bonds.
true
Ions may gain or lose more than one electron to form ionic bonds.
true
Metals generally have smaller electron affinities than nonmetals do.
true
Unpaired electrons are bonding sites for covalent bonds.
true
Electronegativity is a property of ____ atoms
bonded
electronegativity applies only to___
bonded atoms
Only one covalent bond can exist between two atoms
false
in a(n)____ bond , one atom loses almost all influence over its original valence electrons and the other acquires those electrons
ionic
large organic (such as proteins) with unique properties are called
macro molecules
An atom has a stronger attraction for electrons if it has a(n) _____ electron affinity
negative
atoms are generally most stable when they acquire a complete valence energy level. This is statement is called_____
octet
a covalent bond is achieved by ____ electrons
sharing
a covalent bond is achieved by what electrons
sharing
Every diatomic nitrogen molecule has a triple covalent bond. How many electrons does each nitrogen atom contribute to the bond?
three
. In an ionic bond, the electron is more likely to be found near the nonmetal atom.
true
Organic compounds are covalent compounds
true
chemical bonds involve mainly the ___ electrons of the bonding atoms
valence electrons
the electronegativities' of the elements in an ionic bond tend to be ____
very different
Normally atoms are most stable when they_____
attain a full valence shell of electrons
the three vast dimensional particle structure of an ionic compound is called a_____
crystal lattice
A double covalent bond is weaker than a single bond.
false
An element with a positive electron affinity is more stable when it acquires electrons.
false
By definition, diatomic elements contain covalent bonds.
false
Covalent compounds cannot exist as solids at standard conditions.
false
Diatomic elements consist of simple molecules made of the atoms of two different elements.
false
Lewis structures clearly describe the structure of an ionic compound.
false
elements with the lowest electronegativities tend to have ______ valence electrons. Most of these elements are classified as _____
few/metal
the electro negativity the atoms of two different non-metal is ___ zero
greater than
two atoms are most likely to form an ionic bond if they
have greatly different electronegativities
Ionic bonds tend to form between ______ and _________ elements.
metals , nonmetals
the family of elements with the overall lowest electrons if it has an ____ electron affinity
noble gases
how many electrons does the element hydrogen (group 1 A) have to share in covalent bonding?
one
a molecule that contains carbon and at least one hydrogen atom is call an
organic
two atoms with nearly full valence shells and similar electronegativities can bond by________
sharing
Elements with nearly full valence energy levels have high electronegativities.
true
Most metals have only one or two loosely held valence electrons
true
Polar diatomic molecules are partially charged on each end
true
Two atoms of the same nonmetal element bond together to form a diatomic molecule.
true
how many electrons does the element oxygen (group 6A) have to share in covalent bonding?
two
Chemical bonds involve mainly an atoms___
valence electrons
