A mixture of two or more elements, one of which is a metal.
What is an alloy?
100
Alloys are generally ____________ and less likely to react with air or water than are the pure metals from which they are made.
What is stronger?
100
Valence electrons in an atom are those that are__________
A. held most loosely.
B. of the lowest energy level.
C. always easily lost.
D. never easily lost.
What is held most loosely?
100
What does the subscript 2 in H2O mean?
It means there are 2 hydrogen atoms.
100
A chemical bond formed when atoms share three pairs of electrons.
What is a triple bond?
200
An atom or group of atoms that has become electrically charged.
What is an ion?
200
When an atom gains an electron, it becomes a _________________________ ion.
What is negative?
200
The metal atoms in stainless steel are held together by
A. ionic bonds.
B. polar bonds.
C. covalent bonds.
D. metallic bonds.
What is metallic bonds?
200
Why is stainless steel better than iron?
It doesn’t rust.
200
A chemical bond formed when two atoms share electrons.
What is a covalent bond?
300
The electrons that are in the highest energy level of an atom and that are involved in chemical reactions.
What is a valence electron?
300
When an atom loses an electron, it becomes a ___________________ ion.
What is positive?
300
When an atom loses or gains electrons, it becomes a(n) __________
A. ion.
B. formula.
C. crystal.
D. subscript.
What is an ion?
300
Why do noble gases usually not react?
The have 8 valence electrons.
300
The attraction between oppositely charged ions.
What is ionic bond?
400
A representation of the valence electrons in an atom, using dots.
What is an electron dot diagram?
400
The elements within a group have similar properties because they all have the same number of _____________________ in their atoms.
What is valence electrons?
400
A covalent bond in which electrons are shared equally is a _______________
A. double bond.
B. triple bond.
C. polar bond.
D. nonpolar bond.
What is a nonpolar bond?
400
Why do ionic compounds generally have high melting points?
They have strong bonds.
400
A covalent bond in which electrons are shared unequally
What is a polar bond?
500
A combination of symbols that represents the elements in a compound and their proportions.
What is chemical formula?
500
The model of solid metals explains the ease with which they can change shape, their ability to conduct electric current, their luster, and their ability to conduct heat.
What is the “sea of electrons” model?
500
On the periodic table, elements with the same number of valence electrons are in the same ________________
A. square.
B. period.
C. block.
D. group.
What is a group?
500
In metallic bonding positive metal ions are attracted to what?
The “sea” of valence electrons.
500
An attraction between a positive metal ion and the electrons surrounding