Chapter 15 Test Flashcards
What are valence electrons?
The outermost electrons in an atom
How do valence electrons relate to bonding?
These are in the outermost shells of atoms, so they are usually the only electrons involved with bonding.
How do valences relate to group numbers? Is this true for all groups? Which groups is this true for?
They indicate the group number for groups 1A-8A, not the B groups
What is a cation?
A positively charged ion formed when an atom loses electrons
What kinds of elements are cations formed by and why do they do this?
Usually formed by metal atoms to achieve Noble Gas configurations and become stable
What kinds of elements are stable? What makes them stable?
Noble gases are most stable, outer subshells are full
What do all atoms want to do by common nature?
They want to adjust to achieve their lowest possible energy, their most stable energy state
What is an anion?
A negatively charged ion formed when an atom gains electrons
What kinds of elements are anions formed by and why do they do this?
Usually formed by nonmetal atoms to achieve Noble Gas configurations and become stable
What is a monatomic ion?
A single atom ion with only one kind of element
What is the suffix for monatomic ions?
-ide
What are some examples of monatomic ions and their new names?
O-oxygen
O-2-oxide
F-fluorine
F-1-fluoride
What is a polyatomic ion?
A group of different atoms with a charge. The group of atoms acts as a single unit.
What are the endings for polyatomic ions?
-ite and -ate
What is an example of a polyatomic ion?
CO2-carbon dioxide
CO3^-2-carbonate
Who proposed the Octet Rule?
Lewis
What is the Octet Rule?
Atoms react by changing the number of their electrons so as to acquire the stable electron structure of a noble gas
What is the Octet Rule really an explanation of?
Why atoms tend to form their respective types of ions
What is an ionic bond?
The force of attraction that bonds oppositely charged ions together
What kind of forces are present in ionic bonds?
electrostatic attractions
How does the ionic bonding relate to periodic trends?
Because nonmetals are smaller atoms with high EN and IE, they will pull off valence electrons from the metal atoms. they will gain electrons from metal atoms
What do ionic bonds form?
Ionic compounds
Why are all ionic compounds neutral?
The charges of anions plus the cation charges must equal 0.
What is a formula unit?
The lowest whole number ratio of ions in an ionic compound which keeps the identity of that ionic compound
What is a representative particle?
The smallest particle of a substance that keeps that substance’s identity
What are the representative particles for elements and compounds?
Atoms are the RPs for elements
Formula units are the RPs for the ionic compounds
What are some properties of ionic compounds?
- composed of cations and anions
- electrically neutral charge, as cations and anions charges cancel each other
When writing chemical formulas, which ion is writing first?
the cation
What is the pattern structure of an ionic compound?
Crystal structure, repeating 3D pattern
How do group B elements gain or lose electrons?
They lose outer electrons one at a time
What is the coordination number? How does it relate to the atom’s crystal structure?
The number of oppositely charged ions touching a single ion. The shape of the crystal is determined by the ion’s charge and size.
How does an ionic compound’s crystal strength relate to how it conducts electricity?
It must have a free movement of charge to conduct electricity. Crystal structure means that ions are locked into a fixed position and unable to move freely, thus do not conduct electricity.
What is the ionic compound’s level of sturdiness?
They are brittle
How are ionic compounds brittle?
When a force is applied to an ionic compound, like charges are forced together and in response, the like charges repel and the crystal shatters into smaller ones.
What is the ionic compound’s level of solubility?
Readily soluable in water
How are ionic compounds readily soluable in water?
They are easily dissolvable in water; they dissocate (separate into individual ions)
What is the ionic compound’s property of melting point?
High melting point
How do ionic compounds have a high melting point?
Determined by the strength of bonds, as bonds are strong, which raises the melting point, the stronger the bonds, the higher the melting point.
What is the ionic compound’s flammability property?
not flammable
How are ionic compounds not flammable?
They will not combust when put in a flame.
What is the ionic compound’s conductor property?
They conduct in liquids
How do ionic compounds conduct in liquids?
Liquid particles are more free to move around as more bonds break.
Do ionic compounds conduct in solutions?
Yes
Why do ionic compounds conduct in solutions?
Because ionic compounds dissocate when dissolved in water, the ions are free to move around and thus conduct electricity.
What is a metallic bond?
The attraction between the free floating valence electrons and fixed positive nuclei of the metal atoms
What are free floating valences called?
A sea of electrons
Are metallic bonds malleable?
Yes
How are metallic bonds malleable?
They are non-directional in their bonds
How do metallic bonds work with many atoms?
The electrons in between can attract and slide over and attract to more than one atom
Are metallic bonds ductile?
Yes
What is an alloy?
A solution of metals
Are metallic bonds good conductors?
Yes
How are metallic bonds good conductors of heat and electricity?
The free floating valences cause them to slide over one another, attract to other nuclei and therefore transfer the heat and electricity from atom to atom
What do metallic bonds conduct?
heat and electricity
What are the two types of alloys?
substitutional alloys and interstitial alloys
What are substitutional alloys?
Metal atoms in this alloy are the same size
What are interstitial alloys?
Have metal atoms different in sizes at bonding, which causes for interstitial space, as the smaller atoms fit into these spaces
Why are interstitial alloys more dense?
The smaller atoms fit into these interstitial spaces and cause for less room.
How can you tell between hard and soft metals?
If an atom has 3 or more single “d” electrons, then they will bond and form a covalent network in addition to the metallic bonds, making them hard metals.
What elements are the hard metals in the periodic table?
D3-D7 groups
