Chemistry (Chapter 7) Flashcards
S1) How can you determine the number of valence electrons in an atom of a representative element?
Look at its group number.
S1) Atoms of which elements tend to gain electrons? Atoms of which elements tend to lose electrons?
Atoms of metallic elements lose their valence electrons, leaving a complete octet in the lowest energy level. Atoms of some nonmetallic elements gain electrons to achieve a complete octet.
S1) How do cations form?
An atom’s loss of valence electrons produces a positively charged cation.
S1) How do anions form?
The gain of electrons by a neutral atom produces negatively charge anion.
S1) How do you describe the electrical charge of an ionic compound?
Ionic compounds are electrically neutral.
S1) What properties characterize ionic compounds?
Most ionic compounds are crystalline solids at room temperature, and they generally have high melting points. Ionic compounds can conduct an electric current when melted or dissolved in water.
S1) How do chemists model the valence electrons in metal atoms?
The valence electrons of metal atoms can be modeled as a sea of electrons.
S1) How can you describe the arrangements of atoms in metals?
Metal atoms are arranged in very compact and orderly patterns.
S1) Why are alloys more useful than pure metals?
Alloys are important because their properties are often superior to those of their component elements.
How is an anion produced?
It is produced when an atom gains one or more valence electrons.
What is a valence electron?
An electron in the highest occupied energy level of an atom.
What is electron dot structure?
A notation that depicts valence electrons as dots around the atomic symbol of the element; the symbol represents the inner electrons and atomic nucleus; also called Lewis dot structure.
What is the octet rule?
Atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons.
What is the halide ion?
A negative ion formed when a halogen atom gains an electrons.
What is an ionic compound?
A compound composed of positive and negative ions.
What is an ionic bond?
The electrostatic attraction that binds oppositely charged ions together.
What is a chemical formula?
An expression that indicates the number and type of atoms present in the smallest representative unit of a substance.
What is a formula unit?
The lowest whole-number ratio of ions in an ionic compound.
What is a coordination number?
The number of ions of opposite charge that surround each ion in a crystal.
Elements within the same group of the periodic table behave the same because they have the same number _____.
Valence Electrons.
______ on the periodic table indicates how many valence electrons that element has.
Group number.
Diagrams that show valence electrons as dots.
Electron Dot Structure.
States that in forming compounds, atoms tend to achieve the electron configuration of a noble gas.
Octet Rule
The cations of group 1A always have what charge?
Positive one.
What are positively charged ions called?
cations
What are negatively charged ions called?
anions.
What are produced when elements in group 7A gain an electron?
Halide ions.
What is the charge of cation transition metals?
Varies.
What ion has the same electron configuration as argon?
Chloride ion.
Do metals tend to gain or lose electrons?
Lose
Do nonmetals tend to gain or lose electrons?
Gain.
Noble gases are ____ in chemical reactions
nonreactive
Anions and cations attract each other by means of ____.
electrostatic forces.
The forces of attraction that hold ions together..
Ionic bonding.
What are the charge of ions?
neutral.
Why do ions have a neutral charge?
The positive charge of cations equals the negative charge of anions.
What is the lowest whole number ration of ions?
Formula unit.
Almost all ionic compounds are in what state of matter in room temp?
Solid.
Ionic compounds have what type of structure?
Very organized, crystal.
When do ionic compounds conduct an electric current?
When in the liquid state or dissolved in water.
The number of ions of opposite charge surrounding each ion in a crystal?
Coordination number.
Do ionic bonds have high or low melting points?
High.
Why is an ionic compounds able to conduct electric current when melted/is a liquid?
The orderly structure breaks down & cations are able to move freely. It allows electric current to flow between the electrodes.
Most group 1A cations have how many valence electrons?
One to three.
Metals consist of what?
Closely packed cations that are surrounded by a sea of cations.
Why are metals malleable and ductile?
Particles are able to slide past each other.
What are the three ways in which metals can be arranged?
Body-centered, face-centered, and close-packed.
The attraction of valence electrons for positive metal ions?
Metallic bonds.
What is a mixture of two or more elements, at least one of which is a metal?
Alloy.
What type of alloy whose component atoms are different sizes (smaller ones fit into the spaces of the larger ones)?
Interstitial alloy.
Why are metals good conductors of heat?
Electrons can flow freely.
Alloys that are the same size?
Substitutional alloy.
How many neighbors does a body-centered cubic structure have (except those on the surface)?
Eight
How many neighbors does a face-centered cubic arrangement have?
Twelve.
