Basic Chemistry Concepts and Terms

Matter

anything that has mass and takes up volume.

Element

a pure substance that can not be broken down by ordinary means, and has distinct and physical properties.

Atom

the smallest unit of an element that retains the distinct properties of that element.

Nucleus

positively charged protons and neutrally charged (uncharged) neutrons.

Protons

positively charged subatomic particles in the nucleus of an atom. The number of protons also determines which element it is.

Neutrons

subatomic particles in the nucleus of an atom that do not have an electrical charge.

Electrons

very small subatomic particles with almost no mass that surround the nucleus of an atom, are negatively charged, are in constant motion, and determine the bonding properties of an element.

Atomic Number

The number of protons in the nucleus of an atom of a specific element. This number is unique to the type of element.

Isotopes

atoms of the same element can have a different number of neutrons.

Atomic Mass Number

how much mass is in an element. The number shown on the periodic table is in atomic mass units (AMU).

Molecules

atoms linked by chemical bonds.

Chemical Compounds

molecules that contain at least two different kinds of elements.

Organic Molecules

molecules that contain at least one carbon atom.

Organic Compounds

carbon-containing compounds that typically also contain hydrogen and oxygen and may also contain nitrogen, phosphorus, and sulfur.

Chemical Bonds

Interactions between electrons that hold atoms together in molecules or compounds.

Covalent Bonds

when two atoms share a pair of electrons.

Ions

atoms that have gained or lost an electron.

Ionic Bonds

the interaction and attraction between a positively charged and negatively charged ion.

Hydrogen Bonds

when electrons in a covalent bond are unequally shared, one side of a molecule may have a partial positive charge and one side a partial negative charge.

Biomolecules

the four categories of large, carbon-containing molecules: proteins, carbohydrates, lipids, and nucleic acids

Polymers

long chains of repeating units called monomers

Monomers

the individual chemical units of polymers

Proteins

polymers of amino acids that are the most abundant biomolecules in living organisms and serve many functions including enzymes, chemical signals, provide cell structure, protection, receiving information or moving molecules through cell membranes, and much more.

Carbohydrates

also called sugars, they provide energy for cells and can range in size from small single sugars called monosaccharides like glucose, to long polymers of glucose like starch.

Nucleic Acids

these are DNA and RNA, the code of instructions for living cells. They are polymers of a monomer called a nucleotide, which consists of a sugar, a phosphate group, and a nitrogen-containing base (A, T, C, G)

Lipids

these are also known as fats and they are energy storage molecules and found in cell membranes, creating a barrier between the watery world inside cells and the watery world outside of cells.

Soluble

a molecule or compound that can dissolve in water

Polar Molecule

molecules with uneven sharing of electrons and therefore electrical charge

Solution

a combination of water and a dissolved solute

Solute

a dissolved substance, for example salt when it is added to water is a solute

Solvent

the fluid in which a solute is dissolved

Hydrophilic

water-lover

Hydrophobic

water-fearing

Evaporation

when water molecules transition from the liquid state where they are closer together, to the gas state where they are far apart

Condensation

When water vapor or gas returns to the liquid state

Chemical Reaction

the process of breaking chemical bonds and creating new ones

Reactants

the substances that undergo a chemical reaction to create a new substance

Products

the substances that are created by a chemical reaction from the changes in the reactants.

Acid

a hydrophilic substance that can donate hydrogen ions (H+) into a solution

Acidic Solution

a water based solution containing a lot of hydrogen ions (H+).

Base

these are hydrophilic substances that accept hydrogen ions and take them out of the dissolved solution.

Basic Solution

a water based solution that reduces the number of hydrogen ions that are freely floating in it.

pH Scale

a 0-14 scale where low numbers represent acids, 7 is neutral, and numbers greater than 7 are bases.