chemistry - inter/intra molecular bonds

The ________ rule states that atoms tend to gain, lose or share electrons in order to have a full outer shell of eight electrons, also known as an octet.

octet rule

exceptions to the octet rule

Some atoms can have less or more than 8 electrons in their outer shell, violating the octet rule. Examples include hydrogen, helium, beryllium, boron, and elements in period 3 and beyond.

ionic bond

Type of chemical bond formed between atoms by the transfer of electrons. It occurs between a metal and a non-metal. The metal loses electrons to form a positively charged ion, while the non-metal gains electrons to form a negatively charged ion. The resulting electrostatic attraction between the ions holds them together in a crystal lattice structure.

metallic bond

Type of chemical bond formed between metal atoms by sharing their valence electrons, resulting in a lattice structure with strong electrostatic attraction between cations and delocalized electrons. May differ in their strength (cation charge, cation size and delocalized electrons).

covalent bond types

Type of chemical bond where two atoms share a pair of electrons. There are three types: polar, nonpolar and pure. Polar covalent bonds have unequal sharing of electrons, resulting in partial charges. Nonpolar covalent bonds have equal sharing of electrons and no charges. Pure covalent bonds are between two identical atoms, zero electronegativity thus electrons distributed equally.

coordinate bond

A type of chemical bond where one atom donates a pair of electrons to another atom to form a shared pair. It is also known as a dative bond and is represented by an arrow pointing from the donor atom to the acceptor atom.

What factors affect bond length?

Bond length is affected by the size of the atoms or ions involved in the bond, the number of bonds between the atoms, and the electronegativity.

What factors affect the strength of a chemical bond?

The strength of a chemical bond is affected by the distance between the atoms, the number of electrons shared between them, and the types of atoms involved in the bond. Breaking a double bond requires less energy than breaking a single bond.

lewis diagram steps

1. Count the total number of valence electrons in the molecule.
2. Determine the central atom and arrange the atoms around it.
3. Connect the atoms with single bonds.
4. Place the remaining electrons around the atoms to satisfy the octet rule.
5. If there are still electrons left, place them on the central atom as lone pairs.
6. Check the formal charge of each atom to ensure it is stable.

resonances

Resonances are a phenomenon in which electrons are delocalized across multiple atoms, resulting in multiple possible structures. Resonance structures are represented by double-headed arrows and do not actually exist as individual molecules.

VSEPR rules and angles

VSEPR stands for Valence Shell Electron Pair Repulsion

It predicts the 3D shape of molecules based on the repulsion between electron pairs in the valence shell

Lone pairs of electrons take up more space than bonded pairs, resulting in different molecular shapes

Common shapes include linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral

Bond angles are determined by the number of electron pairs around the central atom, with lone pairs causing greater repulsion and smaller bond angles.

london dispersion

London Dispersion is a type of intermolecular force that occurs between non-polar molecules. It is caused by the temporary dipoles that are created due to the movement of electrons in the molecule. The strength of London Dispersion force increases with the size of the molecule and the number of electrons it has. It is the weakest of all intermolecular forces.

dipole-dipole

Dipole-dipole interactions occur between polar molecules when the positive end of one molecule is attracted to the negative end of another molecule. These interactions are stronger than London dispersion forces but weaker than hydrogen bonding.

hydrogen bond

A type of intermolecular bond that occurs when a hydrogen atom is covalently bonded to an electronegative atom and is attracted to another electronegative atom. It is weaker than a covalent or ionic bond, but stronger than a van der Waals interaction.

ion-dipole interaction

Ion-dipole interaction is a type of intermolecular force that occurs between an ion and a polar molecule.

An ___________ is a type of solid that lacks a definite shape and has a disordered arrangement of particles. Examples include glass, rubber, and some plastics.

amorphous solids

determining if a molecule will have a high melting point

Factors that determine if a molecule will have a high melting point include strong intermolecular forces, high molecular weight, and symmetrical shape.

diamond

Property of diamond:

* Giant covalent structure
* Each carbon atom forms four covalent bonds
* High melting and boiling points
* Hard and rigid
* Does not conduct electricity
* Transparent and colorless
* Angle of 109.5 degrees
* allotropes of carbon

graphite

* Form of carbon allotrope with a layered structure.
* Each carbon atom is covalently bonded to three others, forming hexagonal rings.
* Layers are held together by weak van der Waals forces.
* Conducts electricity due to delocalized electrons in the layers.
* Bond of 120 degree.

fullerenes

* Carbon atoms bonded in a 3D network (C60)
* Strong covalent bonds between atoms
* High melting and boiling points
* Insoluble in water
* Conducts electricity in solid state
* allotropes of carbon

Flashcard: Silica Properties

A chemical compound composed of silicon and oxygen atoms in a 1:2 ratio, known for its high melting point, hardness, and resistance to chemicals and electricity.

A ____________ is a group of atoms that carries a charge and behaves as a single unit in chemical reactions.

polyatomic ions