Chem Quiz, Chem Ionic and Covalent Bonds Quiz

What are chemical compounds?

Combinations of atoms held together by chemical bonds

What are the two basic chemical bonds?

Ionic and covalent

How do ionic bonds result?

When one or more electrons from one atom are transferred to another atom

What do the atoms form with ionic bonds?

Positive and negative ions which attract each other

What are ionic compounds composed of?

Large numbers of cations and anions so that the amount of positive charge equals the negative charge

Metals and nonmetals

What is a molecule?

A group of atoms that are bonded together by covalent bonds

What are molecular compounds composed of?

These molecules

Are metals cations or anions?

Cations

Are nonmetals cations or anions?

Anions

What are covalent compounds composed of?

Nonmetals (anions)

What is bond dissociation energy bond type?

Covalent

What are ionic compounds?

Acid/bases (hydroxides, oxides)

Salt

What are polyatomics like?

Group of atoms covalently bonded to one another that possess a charge (so ionic)

Gain/lose of an electron

What is lattice energy?

Energy released when ionic bonds are formed

Negative numbers - the more negative the more energy

Why is lattice energy stronger for smaller ions?

Lattice energy is more for small ions because the attraction is greater

How is electronegativity used to determine bond type?

Through the 0-0.3, etc

How many elements can chemical bonds be between?

2 or more

When do ionic compounds have more conductivity?

In aqueous solutions

What are covalent and ionic bonds considered?

Covalent and ionic are exothermic

What is a chemical bond?

A mutual electrical attraction between the nuclei and valence electrons of diff atoms that binds the atoms together

Why do atoms bond?

To minimize potential energy and create stability

What is ionic bonding?

Bonding that results from the attraction between large numbers of cations and anions

What happens in ionic bonding?

Atoms completely give up electrons

What are ionic compounds formed between?

Metals and nonmetals

What are types of ionic compounds?

Oxides, salt, hydroxides (OH-)

What is the formula unit?

The simplest collection of atoms from which an ionic compound can be created

What are the types of bonds?

Ionic, metallic, covalent

What are covalent bonds like?

Polar and nonpolar covalent

What is polar covalent?

Unequal sharing e-

One atom that is clearly stronger

What is nonpolar covalent?

Equal sharing of e-

Minimal electronegative differences

What group is unlikely to form an ion?

Group 14

What is the ionic bond shaped like?

Crystalline shape minimizes the potential energy

What forms during ionic bonding?

A crystal lattice because it represents a balance of all attractive and repulsion factors

What are properties of ionic compounds?

Melting point, boiling point, and hardness of the compound depends on how strongly the units attract each other

How strong is an ionic compound's bond?

Strong

What are ionic compounds boiling and melting points like?

They are high boiling and melting points

What is the texture of ionic compounds like?

Hard and brittle

Are ionic compounds soluble and conductive?

Yes and conductive when dissolved in water - can conduct electricity in them well

What is the formation of ionic compounds usually?

Exothermic

What does exothermic mean?

A reaction that releases energy as heat

What is lattice energy?

The energy released when one mole of an ionic crystalline compound is formed

What happens when a value is more negative?

The stronger the attraction is

What does a negative value imply?

Energy is being released

What is lattice energy like for smaller ions?

More negative lattice energy

How does the charge of an ion change attraction?

The greater the charge the more attraction

What are polyatomics?

Atoms that are covalently bonded to one another to form a group of atoms that have both molecular and ionic characteristics

WHat is the metallic bond model not?

Not ionic but forms lattice structures

What do metals have mostly?

Completely vacant p orbitals and d orbitals

What do vacant p and d orbitals allow?

Electrons to roam freely (delocalized) forming a sea of electrons

What do seas of electrons tend to form?

Cations

What are metal's melting points like?

High

What are metals conducttivity like?

Electrical/thermal

What can metals do with light?

Absorb it (luster)

Are metals malleable?

Yes

What does the number of delocalized electrons influence?

Hardness/strength

What are metal alloys easy to?

Introduce other materials into metallic crystal

What is an alloy?

Mixture of elements that have metallic properties

Mostly metals but some nonmetals

What are examples of alloys?

Steel, bronze, brass, aluminum, nichrome, titanium, berrylim-copper, nickel, copper-nickel, niobium

What are the different kinds of alloys?

Subsitution and interstitial

What does covalent compounds and bonding result from?

Sharing of electron pairs between two neutral atoms

Equal

What is the result of covalent compound?

Equal

What is an example of a covalent bond?

Diatomic molecules

What type of covalent are diatomic molecules?

Non-polar covalent

All electrons are shared evenly

What are electrons more attracted to?

The more electronegative atom

What does the electronegativity of the atoms help determine?

Whether atoms will form ionic or covalent bonds

What is the range of two numbers that are nonpolar covalent?

0 - 0.3 (inclusive)

What is the range of two numbers that are polar covalent?

0.3 (exclusive) - 1.7 (inclusive)

What are the numbers that are an ionic bond?

1.7 < #

What is a molecule?

Neutral group of atoms that are held together by covalent compounds

What is a molecular compound?

A chemical compound whose simplest units are molecules

COVALENTLY BONDED

What is a chemical formula?

Shows the relative number of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts

NaCl

Show the simplest ratio

What is a molecular formula?

Shows the types and numbers of atoms combined in a single molecule of a moleacular compound

C6H12O6

What is a diatomic molecule?

A molecule with only two atoms

HOFBrINCl

How do covalent bonds form?

At maximum attraction, the repulsive forces balance the attractive forces

What is bond length?

The distance between the nuclei of bonded atoms at the minimum potential energy

Does a shorter or longer bond release more energy?

Shorter bond

Why does a shorter bond release more energy?

Because there is more energy required to break the bond

What happens when covalent bonds form?

Atoms release energy

What is bond dissociation energy?

The amount of energy required to break the bond

Higher energy = stronger bond

What happens as the number of shared electrons increases?

Bond length decreases - double/triple bonds

How many electrons do single, double, and triple bonds share?

Single = 2e-

Double = 4e-

Triple = 6e-

How are molecular and ionic characteristics similar?

Both molecular (covalent) and ionic bonds are formed for the same reason: to help atoms reach a more stable, lower-energy state

Usually, this means trying to get a full outer shell of electrons (the Octet Rule)

What is electronegativity?

Electronegativity is the ability of an atom to attract shared electrons in a bond

What is negative energy also considered as?

Less energy

What are metallic propeties?

Metallic properties are the physical and chemical characteristics of metals, primarily driven by their ability to easily lose valence electrons (low ionization energy)

What are ionic properties?

Ionic compounds are characterized by high melting and boiling points, crystalline structures, and high solubility in water

What are covalent properties?

Covalent compounds have low melting/boiling points, poor electrical conductivity, and existence as gases, liquids, or soft solids

Why do metallic compounds form?

Metallic forms because the positive atoms cluster together and the electrons float around in the cloud freely among all the atoms

What are covalent bonds between?

Nonmetal and a nonmetal

What are ionic bonds between?

Metal and a nonmetal

Why do crystalline structures form?

Maximizes attraction (opposites close together)

Minimizes repulsion (like charges kept apart)

Lowers energy → more stable

Can alloys be separated?

Yes because its a mixture not a compound

What is the octet rule?

Chemical compounds tend to form so that each atom by gaining, or losing, or sharing electrons, has an octet (8) of electrons in its highest occupied energy level

What are lone pairs?

An unshared pair of electrons that are not involvedd in bonding and belong to only one atom

What do the pair of dots in Lewis Structures represent?

The pairs of dots between two element symbols represents the shared pair of electrons

What does one line of a bond between two atoms equal?

2 electrons

How many other electrons does hydrogen bond to?

Only one

Do you add dots to hydrogen in a lewis dot structure?

No only if H hydrogen is bonded within a molecule, that dot is paired with another electron from a different atom to form a single bond

What are the exceptions to the octet rule?

If there is an expanded octet which occur in period three or above

Free radicals (odd number of electrons) - there is one extra electron not in a pair

Incomplete octet (H, Be, and B)

What do unbonded pairs do easier?

Bond with others