Unit 5: Bonding Flashcards
(48 cards)
Ionic Bond Materials
Metals with Non-metals
Covalent Bond Materials
Non-metals with Non-metals
Metallic Bond Materials
Metals
Explain Metallic Bonding
Solid metals exist as a lattice. The atoms let go of their electrons, creating Delocalised Electrons. Letting go of e- turns all the atoms into + ions.
Now we have + ions and e- in a lattice. Of course there will be a lot of electrostatic forces.
Properties of a Metallic Bond
Very Strong (High boiling point)
Very Conductive (because of delocalised electrons)
Pure Metals - Malleable and Ductile (because the lattice slides easily without alloy structure)
Explain Ionic Compounds
Metals like to donate electrons and non-metals like to accept electrons, because metals have a lower valency and non-metals have a higher valency. Thus they lean toward the least energy needed.
eg. Mg needs to lose 2 electrons and O needs to gain 2 electrons. Thus, it will donate.
This adds a +2 charge on Mg and -2 charge on O. They get attracted to the charges due to electrostatic forces.
Properties of Ionic Compounds
Very Strong (High melting point) - due to electroststic forces
Can Conduct
Brittle - due to structure
Why are Ionic Compounds Brittle?
Ionic Compounds exists as crystalline structures/ionic solids, where ions are located in specific positions.
A hammer blow distorts the arrangement, brining like-charged ions cost together due t the sliding nature of the structure. Causing the compound to shatter.
Covalent Bonds
When 2 unstable non metals share electrons to complete their outer shells, bonding them.
Properties of Covalent Bonds
Do not conduct electricity - no free electrons
Not soluble in water.
Low melting and boiling points.
Intermolecular Forces
The forces between a molecule (like h20) and another molecule. Often Occur in Covalent Bonds.
Intramolecular Forces
The forces between atoms (like Hydrogen and Oxygen)
Polar and Non-Polar molecules
Polar: When the electrons in an atom/molecule are unequal. Example, Hydrogen and Fluorine. Fluorine is very electronegative. So, in their covalent bond, it ends up pulling the electrons. However, not fully. So instead of a negative charge toward F, we use a partial-. At the same time making H partially +.
So a polarised covalent bond would look like: partial+H partial-F
This also establishes + and - poles as dipoles.
Non Polar: When electrons are equally distributed. Like, have the same electronegativity or not a large enough different. Producing so partial charges.
Electronegativity
More electronegativity = More attractive the element is to electrons
Electron Cloud
Just the general electrons
Polarised
A state where the atom/molecule has unequal electron distribution through to partial charges.
Name the intermolecular forces
Dipole-Dipole interactions, Vander Waals and Hydrogen Bonds
Permanent Dipole-Dipole
The the partial - from one molecule attracts the partial - from another through electrostatic forces.
Temporary Dipole
Because electrons are constantly moving, at some point they end up imbalanced with more electrons on 1 side. This makes the electron heavy side the partial- pole and vice versa. Thus making it a temporary Dipole, because once the electrons go back to normal, the poles will balance out.
Induced Dipole
When a Temporary Dipole uses its partial- or + charge to induce a temporary dipole. Like by attracting the electrons to 1 side with a partial +.
This makes that atom polarised as well.
Vander Walls Force
The Temporary attraction between the partial+ of a temporary dipole and the partial- of an induced/temporary dipole.
Strength of Dipole Dipole Interactions/Vander Walls Force
Very weak
Hydrogen Bonds
Hydrogen + An electronegative atom like F, O or N (usually)
(Example: H20)
- Strongest intermolecular force, but weaker than intramolecular forces
Name the 3 possible ion and dipole interactions
ion-ion (formal charge)
ion-dipole
dipole-dipole
