Atoms, Bonding, and the Periodic Table Flashcards
What is the definition of Valence electrons?
electrons that have the highest energy level and are held most loosely
Key concept: The number of valence electrons in an atom of an element determines…
many properties of the element, including the ways in which the atom can bond with other atoms
What is the definition of an electron dot diagram?
a diagram that include the symbol for the element surrounded dots that stand for one valence electron
What are the two ways atoms usually react that makes it more stable?
- the number of valence electrons increase to eight.
- The atoms gives up loosely held valence electrons
What is the definition of a chemical bond
the force of attraction that holds two atoms together as a result of the rearrangement of electrons between them
Key Concept: the Periodic table reveals the…
underlying atomic structure of atoms, including the arrangement of the electrons
How many valence electrons does group 1 have?
1
How many electrons does group 2 have?
2
How many valence electrons does group 13 have?
3
How many valence electrons are in group 14?
4
In group 18 are…
the inert gases t hat consist of eight valence electrons except for helium, who has 2
The Elements in Group 17..
are halogens that have 7 valence electrons
What is the definition of an ion?
an atom or group of atoms that has an electric chage
When an atom loses an electron…
it loses a negative charge and becomes a positive ion
When an atom gains an electron..
It gains a negative charge and becomes a negative ion
What is the definition of a polyatomic ion?
Ions that are made of more than one atom
What is the definition of an ionic bond?
The attraction between two oppositely charged ion
Key concept: ionic bonds form as a result of the attraction between…
positive and negative ions
What is the definition of an ionic compound?
a compound that consists of positive and negative ions, such as sodium chloride
What is the definition of a chemical formula?
a combination of symbols that shows the ratio of elements in a compound
Key concept: When ionic compounds form the ions come together in a way that balances out…
the charges on the ions
What is the definition of a subscript
the ratio of elements in the compound
Key concept: For an ionic compound, the name of the positive ion…
comes first, followed by the name of the negative ion
Key concept: In general, ionic compounds are…
hard, brittle, solid with high melting points that when melted or dissolved in water, they conduct electric current
What is the definition of a covalent bond?
the chemical bond formed when two atoms share electrons
Key concept: the force that hold atoms together in a covalent bond is the attraction of each…
atom’s nucleus for the shared pair of electrons
What is the definition of a double bond?
two atoms that share two pairs of electrons
What is the definition of a triple bond?
atoms share three pairs of electrons
What is the definition of a molecular compound?
a compound that is composed of molecules that contain atoms that are covalently bonded
Key concept: compared to ionic compounds, molecular compounds generally have…
lower melting and boiling points, they do not conduct electric current when melted or dissolved in water
Key concept: unequal sharing of electrons causes the bonded atoms to have…
slight electrical charges
What is the definition of a polar bond?
a covalent bond in which electrons are shared unequally
What is the definition of a nonpolar bond?
a covalent bond in which electrons are shared equally
What is the definition of an alloy?
a mixture made of two or more elements at least one of which is a metal
Key concept: Alloys are generally stronger and …
less reactive thant the pure metals from which they are made
Key concept: metal atoms combine in regular patterns in which the valence electrons are…
free to move from atom to atom
What is the definition of a metallic bond?
an attraction between a positive metal ion and the many electrons surrounding it
Key concept: The “sea of electrons” model of metallic bonding helps explain the…
malleability, ductility, luster, high electrical/thermal conducting of solid metals
