Basic Chemistry Concepts: Matter, Atoms, Bonds, and Solutions

Matter

Anything that has mass and occupies space and is made up of atoms

Atoms

Smallest functional units of matter that form all chemical substances

Protons

Center of the atom (atomic nucleus), positive charge

Neutrons

Center of the atom, neutral charge

Electrons

At various distances from the nucleus (in orbitals - max 2 electrons), negative charge

Molecules

Two or more atoms bounded together

Element

Each specific type of atom

Net positive charge = ?

The number of protons

Energy

Capacity to do work or cause change

Electron shells

Where orbitals are found, can hold up to 8 electrons total other than the first electron shell (2 electrons)

Valence electrons

Electrons in the outermost shells

Atomic number

The number of protons and the number of electrons

Atomic mass

An atom's mass relative to other atoms, measured in Daltons (Da)

Isotopes

A form of an element that contains a different number of neutrons

Radioisotope

An unstable isotope that emits energy as radiation when they decay

Mineral elements

Chemical elements other than oxygen, hydrogen, carbon, and nitrogen that are required for life

Trace elements

Elements present in extremely small quantities but are essential for normal growth and function

Molecular formula

Chemical symbol for all present atoms

Structural Formula

Each covalent bond is shown with a line connecting the elements

Compound

A molecule with two or more different elements

Covalent bonds

Two atoms share a pair of electrons

Octet rule

Atoms are more stable when their valence shells are full

Double bond

Atoms share two pairs of electrons

Electronegativity

Measure of its ability to attract electrons in a bond with another atom

Nonpolar covalent bonds

Covalent bond formed between two atoms of similar electronegativities and electrons are shared equally

Polar covalent bonds

Covalent bond formed between two atoms of different electronegativities

Hydrogen bonds

Hydrogen atom in one polar molecule becomes electrically attracted to an electronegative atom

Enzyme

A protein that acts as a catalyst to speed up a chemical reaction in a cell

Van der Waals dispersion forces

Weak molecular attractions

Ion

Gains a net electric charge and gains or loses one or more electrons

Cations

Positive charge

Anions

Negative charge

Ionic Bond

Cation bonds to an anion

Ionic Compounds

Atoms are held together by ionic bonds

Free radical

A molecule with an atom with a single unpaired electron in its outer shell

Antioxidants

A molecule that can donate an electron without becoming highly reactive

Chemical reaction

One or more substances are changed into other substances by making or breaking bonds and/or adding or removing electrons

Solutes

Substances that dissolve in liquid

Solvent

Liquid that solutes dissolve in

Solution

When a solute dissolves in a solvent

Aqueous solution

Solutions made with water

Hydrophilic

Ionic and polar molecules easily dissolve in water

Hydrophobic

Nonpolar molecules with few or no partial positive and negative charges and do not dissolve in water

Amphipathic

Molecule with both hydrophobic and hydrophilic regions

Micelle

Sphere formed from amphipathic molecules when they are mixed with water

Solute Concentration

The amount of a solute dissolved in a unit volume of solution

Molecular mass

Sum of the atomic masses of all the atoms in the molecule

Molarity

Mol/L

Heat of vaporization

Heat required to vaporize 1 mole of any substance at its boiling point

Heat of fusion

Amount of heat that must be released from a substance to cause it to change from the liquid to the solid state

Specific Heat

The amount of heat required to raise the temperature of 1 gram of a substance by 1°C

Heat Capacity

Amount of heat required to raise the temperature of an entire object or a particular amount of a substance

Colligative properties

A property of a solution that depends only on the total number of dissolved solute particles

Hydrolysis reactions

Chemical reaction that utilizes water to break apart other molecules

Cohesion

Ability of like molecules to noncovalently bind to each other; the attraction of water molecules for each other

Adhesion

The ability of molecules of two different substances to bind to each other

Surface tension

Measure of the attraction between molecules at the surface of a liquid

Acids

Substances that release H+

Strong Acids

Completely dissociates into H+ and other elements

Weak Acids

Does not completely dissociate

Base

Substance that decreases the [H+]

pH

Measure of H+ concentration in a solution

pH = -log[H+]

Formula for calculating pH

Acidic

Contains more [H+] than [OH-]

Alkaline

pH above 7

Buffer

A pair of substances that minimizes pH fluctuations in the fluids of living organisms

Most stable state of water

liquid