Chapter 6 - Part Two Flashcards
What are most of the rocks and minerals that make up earth’s crust consisted of?
Positive and negative ions held together by ionic bonding
What do most ionic compounds exist as?
Crystalline solids
What is a crystal?
A three-dimensional network of positive and negative ions mutually attracted to each other
What does a chemical formula of an ionic compound represent and how does that differ from molecular compounds?
It represents the simplest ratio of the compound’s ions, not independent, neutral atoms that can be isolated.
What is a formula unit?
The simplest collection of atoms from which an ionic compound’s formula can be established
Ex: NaCl
Why do ions form a crystal lattice and what does that look like?
They want to minimize their potential energy
Attractive forces between opposite charges; repulsive forces between like charges
The combined forces determine the distance between ions and the pattern of their arrangement
What is lattice energy?
The energy released when one mole of an ionic crystalline compound is formed from gaseous ions
Compare the bonds in ionic and covalent compounds
The forces that hold ions together is a very strong electrostatic charge, but the forces of attraction between molecules in a covalent compound are much weaker
What is the general melting point and state of molecular compounds?
Low melting points, exist as liquids and gases
What is the general melting point, state, quality, and ability to conduct electricity (solid and liquid) of ionic compounds?
High melting/boiling points, hard/brittle solids, only good conductors in a liquid state or when dissolved in water
What is a polyatomic ion?
A charged group of covalently bonded atoms
What is different about the energy levels in metals?
The vacant orbitals in the atom’s outer energy levels overlap
Describe the movement electrons in a metal and what they form
They can roam freely because they are delocalized; they form a sea of electrons
What is metallic bonding?
The chemical bonding that results from the attraction between metal atoms and the surrounding sea of elections
What are the four metallic properties and why?
Electrical/thermal conductivity (electrons can move), shiny appearance (electrons jump to a higher energy state, then quickly fall), malleability and ductility (atoms can get close without breaking any bonds)
Describe an molecule with two bonds and no pairs of electrons by electron domain geometry and molecular geometry
Linear/linear
Describe an molecule with three bonds and no pairs of electrons by electron domain geometry and molecular geometry
Trigonal planer/ trigonal planer
Describe an molecule with two bonds and one pair of electrons by electron domain geometry and molecular geometry
Trigonal planer/bent
Describe an molecule with four bonds and no pairs of electrons by electron domain geometry and molecular geometry
Tetrahedral/tetrahedral
Describe an molecule with three bonds and one pair of electrons by electron domain geometry and molecular geometry
Tetrahedral/trigonal pyramidal
Describe an molecule with two bonds and two pairs of electrons by electron domain geometry and molecular geometry
Tetrahedral/bent
What is an ionic compound composed of?
Positive and negative ions that are combined so that the numbers of positive and negative charges are equal
What is molecular polarity?
The uneven distribution of molecular charge
What does VSEPR stand for?
Valence-Shell Electron Pair Repulsion Theory