Chapter 2: The Nature of Molecules and the Properties of Water (copy)

Atoms

The basic building blocks of matter, composed of protons, neutrons, and electrons.

Protons

Positively charged subatomic particles located in the nucleus of an atom.

Neutrons

Neutral subatomic particles located in the nucleus of an atom.

Electrons

Negatively charged subatomic particles found in orbitals surrounding the nucleus of an atom.

Atomic Number

The number of protons in an atom, which determines the element.

Atomic Mass

The sum of protons and neutrons in an atom, which gives the atom's mass.

Ions

Charged particles formed when an atom gains or loses electrons.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Electron Arrangement

The number and arrangement of electrons in the orbitals of an atom, which determines its chemical behavior.

Valence Electrons

The electrons in the outermost energy level of an atom, responsible for chemical bonding.

Covalent Bonds

Chemical bonds formed when atoms share two or more valence electrons.

Hydrogen Bonds

Weak chemical associations formed between the partially negative oxygen atom of one water molecule and the partially positive hydrogen atom of another water molecule.

Acids

Substances that increase the concentration of hydrogen ions (H+) in a solution, lowering the pH.

Bases

Substances that combine with hydrogen ions (H+) in a solution, raising the pH.

Buffers

Substances that resist changes in pH by releasing or absorbing hydrogen ions in a solution.