Topic 01 - Structure of Water and Hydrogen Bonding

Matter

Anything that takes up space and has mass

Element

A substance that cannot be broken down into other substances by chemical reactions

Electronegativity

The measure of an atom’s ability to attract electrons to itself. Increases from left to right, and decreases from top to bottom.

Atomic Number

Number of protons

Atomic Mass

Number of protons plus neutrons averaged over all isotopes

Octet Rule

Elements will gain, lose, or share electrons to complete their valence shell and become stable (like noble gases)

Chemical Bonds

An attraction between two atoms, resulting from the sharing or transfer of valence electrons

Compound

A substance consisting of two or more different elements combined in a fixed ratio

Covalent Bonds

When two or more atoms share electrons (usually between nonmetals) forms molecules and compounds.

Nonpolar Covalent Bonds

Electrons are shared equally between two atoms

Polar Covalent Bonds

Electrons are not shared equally between two atoms

Ionic Bonds

The attraction between oppositely charged atoms (ions). Usually between a metal and nonmetal.

Adhesion

The attraction to other molecules that are polar or have charge (H2O to other molecules).

Cohesion

The attraction of molecules for other molecules of the same kind (H2O to H2O).

Capillary Action

The upward movement of water due to the forces of cohesion, adhesion, and surface tension. Occurs when adhesion is greater than cohesion.

Solvent

Dissolving agent in a solution

Solution

Homogenous mix of 2+ substances

Solute

Substance that is dissolved

pH

A measure of how acidic or basic a solution is

Acid

A substance that releases hydrogen ions (H+) when dissolved in water

Base

A substance that accepts H+ and hydroxide ions (OH-)