Chapter 2 Basic Chemistry - Vocabulary Flashcards

A set of vocabulary flashcards covering key concepts from Basic Chemistry: matter, elements, atoms, subatomic particles, periodic table, isotopes, electron structure, bonding, molecules, and water polarity.

Matter

Anything that has mass and occupies space; exists in solid, liquid, gas, or plasma states.

Element

A substance that cannot be broken down into substances with different properties; composed of one type of atom.

Atom

The smallest unit of an element that retains its properties; composed of protons, neutrons, and electrons.

Proton

Positively charged subatomic particle located in the nucleus; +1 AMU.

Neutron

Electrically neutral subatomic particle located in the nucleus; ~1 AMU.

Electron

Negatively charged subatomic particle located in electron shells; very small mass.

Nucleus

Central part of an atom containing protons and neutrons.

Electron shell (energy level)

Regions around the nucleus where electrons are found; energy increases with distance from the nucleus.

Atomic number

Number of protons in an atom’s nucleus; equals the number of electrons in a neutral atom.

Mass number

Sum of the numbers of protons and neutrons in the nucleus; approximately equal to atomic mass.

Isotope

Atoms of the same element with different numbers of neutrons and thus different mass numbers.

Periodic table

Chart of elements arranged by increasing atomic number; periods are rows, groups are columns.

Period

Horizontal row on the periodic table.

Group

Vertical column on the periodic table; elements in a group share similar bonding characteristics.

Noble gases

Group VIII elements; inert and highly unreactive.

Valence electrons

Electrons in the outermost electron shell; determine chemical properties.

Octet rule

Outer shell is most stable with eight electrons (except when only one shell exists, which is stable with two).

Electron shell capacity

First shell holds up to 2 electrons; each additional shell up to 8; lower shells are filled before higher ones.

Ion

An atom that has gained or lost electrons, resulting in a net charge.

Ionic bond

Bond formed by transfer of electrons; oppositely charged ions attract (salts often dissociate in water).

Covalent bond

Bond formed by sharing a pair of valence electrons to achieve a full outer shell.

Nonpolar covalent bond

Covalent bond in which electrons are shared equally between atoms.

Polar covalent bond

Covalent bond in which electrons are shared unequally, creating partial charges; example: water.

Electronegativity

Ability of an atom to attract electrons toward itself in a chemical bond.

Molecule

Two or more of the same or different atoms bonded together; the smallest unit that retains the properties of a substance.

Molecule of element

A molecule consisting of atoms of the same element (e.g., O2, N2).

Molecule of compound

A molecule containing at least two different elements bonded together (e.g., H2O, CO2).

Formula

Indicates the number of each kind of atom in a molecule (e.g., C6H12O6 for glucose).

Salt

Ionic compound formed by ionic bonds; salts dissociate into ions in water.

Sodium chloride (NaCl)

Common table salt; example of an ionic compound formed from Na+ and Cl-.},{