General, Organic, and Biochemistry Lecture Notes

Vocabulary flashcards covering basic matter concepts, measurement systems, periodic table trends, and chemical bonding principles from Chapters 1, 3, and 4.

Matter

Anything that has mass and occupies space.

Mass

A measurement of the amount of matter in an object that is independent of the location of the object.

Weight

A measurement of the gravitational force acting on an object which depends on the location of the object.

Physical properties

Properties of matter that can be observed or measured without attempting to change the composition of the matter being observed, such as color and size.

Chemical properties

Properties that matter demonstrates when attempts are made to change the matter into new substances, such as the ability of paper to burn.

Physical changes

Changes that do not change the composition of the substance, such as cutting a piece of paper.

Chemical changes

Changes in matter that lead to a change in composition, such as the burning of magnesium metal.

Molecule

The smallest particle of a pure substance that has the properties of that substance and is capable of a stable independent existence.

Atoms

The limit of chemical subdivision for matter.

Diatomic molecules

Molecules that contain two atoms.

Triatomic molecules

Molecules that contain three atoms.

Polyatomic molecules

Molecules that contain more than three atoms.

Homoatomic molecules

Molecules that contain only one kind of atom.

Heteroatomic molecules

Molecules that contain two or more kinds of atoms.

Pure substance

Matter with constant composition and a fixed set of properties that cannot be physically separated into simpler substances.

Mixture

Matter in which the proportions of components may vary and can be physically separated into two or more pure substances.

Solutions

Homogeneous mixtures of two or more pure substances.

Heterogeneous matter

Matter with properties that are not the same throughout the sample, where properties depend on the location from which the sample was taken.

Elements

Pure substances made up of homoatomic molecules or individual atoms of the same kind.

Compounds

Pure substances made up of heteroatomic molecules or individual atoms of two or more different kinds.

Basic unit of measurement

A specific unit from which other units for the same quantity are obtained by multiplication or division.

Derived unit of measurement

A unit obtained by multiplication or division of one or more basic units.

Scientific notation

A way to express numbers in the form $M \times 10^n$, where $M$ is a number between 1 and 10 and $n$ is a whole number exponent.

Significant figures

Numbers in a measurement that represent the certainty of the measurement plus one number representing an estimate.

Exact numbers

Numbers that have no uncertainty, such as defined relationships (e.g., $100\,cm = 1\,m$) or counting numbers, and do not limit significant figures in calculations.

Factor-unit method

A systematic approach to solving numerical problems by multiplying a known quantity by factors to cancel units and generate the desired unknown units.

Percentage

The number of specific items in a group of 100 such items, calculated as $\frac{\text{part}}{\text{total}} \times 100$.

Density

The mass of a sample of a substance divided by the volume of the same sample, expressed as $d = \frac{m}{V}$.

Periodic Law

The principle that elements with similar chemical properties occur at regular intervals when arranged in order of increasing atomic numbers.

Groups (or Families)

Vertical columns in the periodic table containing elements with similar chemical properties.

Periods

Horizontal rows of elements in the periodic table arranged according to increasing atomic numbers.

Valence Shell

The outermost and highest-energy shell of an element that contains electrons.

Metals

Elements found in the left two-thirds of the periodic table characterized by high thermal and electrical conductivities, ductility, malleability, and metallic luster.

Nonmetals

Elements found in the right one-third of the periodic table that occur as brittle, powdery solids or as gases.

Metalloids

Elements forming a diagonal separation zone between metals and nonmetals with properties intermediate between the two.

Ionization energy

The energy required to remove an electron from an element in the gaseous state.

Lewis Structures

Representations of an atom or ion where the elemental symbol represents the nucleus and dots represent the valence-shell electrons.

Octet Rule

The rule stating that atoms will gain or lose sufficient electrons to achieve an outer electron arrangement identical to that of a noble gas, usually eight electrons.

Simple ion

An atom that has acquired a net positive or negative charge by losing or gaining electrons.

Ionic bonds

The attractive force between positive and negative ions that holds them together.

Binary ionic compound

An ionic compound formed by the reaction of only two elements, typically a metal and a nonmetal.

Formula weight

The sum of the atomic weights of the atoms shown in the formula of an ionic compound.

Electronegativity

The tendency of an atom to attract shared electrons of a covalent bond.

Polar covalent bond

A covalent bond in which the bonding electrons are shared unequally.

Nonpolar covalent bond

A covalent bond in which the bonding pair of electrons is shared equally by the bonded atoms.