Chapter 7 Flashcards
Valence electrons
the electrons in the highest occupied energy level of an element’s atoms
The only electrons used in chemical bonds
valence electrons
Group number
shows the number of valence electrons in representative elements
Octet rule
atoms tend to achieve the electron configuration of noble gases when forming compounds
Cation
a positively charged ion that lost valence electrons
Na cations
generally unreactive
Most common cations
produced from metals
Cation name for metals
the same as the name of the element
Anion
negatively charged ion that gained electrons
Anion names
not the same as the nonmetallic element name, generally ends in -ide (e.g. chloride)
A formula unit
the lowest whole-number ratio of ions in an ionic compound
Ionic compound
compounds composed of cations and anions, electrically neutral
Ionic bond
the electrostatic force that holds ions together in an ionic compound
Properties of ionic compounds
crystalline solids at room temperature, high melting points, good conductors when melted or dissolved in water
Coordination number
the number of oppositely charged ions that surround an initial atom in a compound
Sea of electrons
the valence electrons of metal atoms
Sea of electrons explains
good conductors (free-flowing electrons) and ductility and malleability (highly mobile electrons)
Types of crystalline structures
body-centered cubic, face-centered cubic, hexagonal close-packed
Body-centered
chromine
Face-centered
gold
hexagonal close-packed
zinc
Alloy
a mixture composed of two or more elements, at least one of which is a metal, properties are superior to those of the component elements
Alloy example
Brass - zinc and copper
Same sized atoms in an alloy
can replace each other, substitutional
Different sized atoms in an alloy
smaller ones can fit into the spaces between larger ones, interstitial
Interstitial example
steels
