Biology 1140: Atoms, Molecules, and Chemical Bonds

Vocabulary practice flashcards covering atomic structure, chemical bonding, chemical reactions, and pH levels as presented in BIOL 1140 notes.

Neutron

A subatomic particle located in the nucleus of an atom with a neutral (no) charge.

Proton

A subatomic particle located in the nucleus of an atom with a positive electrical charge.

Electron

A subatomic particle that orbits the nucleus in energy levels (shells) and has a negative electrical charge.

Atomic number

A value determined by the number of protons associated with a specific element.

Major elements of the human body

The four specific elements—Oxygen, Carbon, Hydrogen, and Nitrogen—that make up approximately $96\%$ of the human body.

Covalent bond

A chemical bond in which electrons are shared between two or more atoms; it is the strongest type of bond found in living organisms.

Ionic bond

A chemical bond resulting from the attraction between negative and positive ions.

Hydrogen bond

An electrical attraction between a hydrogen and another negative atom such as oxygen, nitrogen, or fluorine; it gives $H_2O$ its unique characteristics and is vital to the structure of proteins and DNA.

Polar covalent bond

A bond in which electrons are unequally shared between atoms, which affects the overall charge of the molecule.

Energy shells

The levels where electrons are found around a nucleus; the first shell can hold a maximum of 2 electrons, while the second can hold 8.

Ion

Atoms that vary in the number of electrons found around their nuclei, resulting in a net electrical charge.

Isotope

A variant of an element that differs in the number of neutrons found in the nucleus.

Reactants

The starting materials in a chemical reaction, such as $2HCl$ and $Mg$ in the equation: $2HCl + Mg \rightarrow MgCl_2 + H_2$.

Products

The substances formed as a result of a chemical reaction, such as $MgCl_2$ and $H_2$ in the equation: $2HCl + Mg \rightarrow MgCl_2 + H_2$.

Acids

Chemical compounds that donate a hydrogen ion ($+H$) to a solution.

Bases

Chemical compounds that accept a hydrogen ion ($+H$) from a solution.

pH scale

A scale used to measure the concentration of hydrogen ions in a substance.

Alkalinity (Basic vs. Acidic)

A measurement on the pH scale where higher numbers are more basic; for example, bleach (pH 12) is more basic than baking soda (pH 9).