Atoms, Molecules & Life Vocabulary

Vocabulary flashcards covering fundamental chemistry, chemical bonds, and the unique properties of water from Chapter 2.

Chemical

Anything made of atoms.

Atom

The smallest chemical building block.

Element

A single type of atom that serves as the chemical identification of an atom and cannot be subdivided by chemical reactions.

Molecule

A chemical combination of two or more atoms in a discrete unit.

Chemical Compound

A substance composed of different elements.

Molecular Compound

A compound formed by covalent bonds, such as $H_2O$.

Ionic Compound

A compound composed of positive and negative ions of different atoms, such as $NaCl$.

Covalent Bonds

Bonds formed by the sharing of electrons between atoms.

Ionic Bonds

Bonds formed by the donation and acceptance (transfer) of electrons, resulting in attraction between oppositely charged ions.

Partial Charge / Polar Interactions

Weak chemical bonds resulting from the attraction between molecules with uneven charge distribution due to partial charges rather than full ions.

Hydrogen Bonds

Interactions occurring between two partial charges ($H^{\frac{+}{}}$ / $H^{\beta+}$ and $atom^{\beta-}$) due to a polar covalent bond.

van der Waals Forces

Temporary regions of charge caused by the movement of electrons that help maintain the 3D shape of macromolecules.

Acid

A chemical that adds or contributes $H^+$ (protons).

Base

A chemical that removes $H^+$.

pH Scale

A logarithmic scale used to measure the concentration of $H^+$.

Buffers

Substances that regulate or maintain pH by gaining or losing $H^+$ ions to neutralize strong acids and bases.

Cohesion

The property of water molecules sticking together, which causes surface tension.

Adhesion

The property of water molecules sticking to other surfaces.

Capillary Action

A phenomenon caused by cohesion and adhesion that allows water to move through channels, such as up a tree trunk.