Science Exam Review

Accuracy

How close you are to the actual value.

Precision

How finely tuned your measurements are, producing consistent results.

Democritus

Stated that all matter was made up of tiny particles that could not be broken down into smaller parts.

Mendeleev

Created periodic law, the basis for the periodic table.

Rutherford

Discovered the nucleus of the atom during his gold foil experiment.

Element

A pure substance that can not be broken down further by chemical means

Atom

The smallest unit of matter that still retains the properties of an element.

Energy

The ability to do work.

Heat

When thermal energy flows.

Diffusion

Objects will move from a higher concentration to a lower concentration until they reach a thermal equilibrium.

Kinetic Energy

The energy of motion.

Potential Energy

Stored energy.

Conduction

The transfer of heat through the direct contact of particles

Convection

Occurs in liquids and gases and is the transfer of energy in a fluid by the movement of heated particles.

Radiation

The transfer of energy through electromagnetic waves.

Ionization energy

The energy required to remove an electron from a neutral atom.

Electronegativity

The ability of an atom to attract electrons.

Chemical Bonds

An attractive force between two atoms or ions that bonds them together as a unit.

Chemical Formula

A shorthand representation of a substance using the symbols of the atoms and subscripts to indicate the number of atoms.

Ionic Bond

Formed between a metal and nonmetal and becomes ions due to the transfer of electrons,

Covalent Bond

Bond formed by the sharing of electron pairs.

Polar Covalent bond

Covalent bond where electrons are shared inequally

Non polar Covalent Bond

Covalent bond where electrons are shared equally.

Dipole

A region of positive and negative charge in a molecule or formula.

Polyatomic Ion

A group of covalently bonded atoms that act together as a single ion.

Subscript

The little number following a chemical symbol that tells the number of atoms in that type of formula.

Derived Unit

Two simple units combined.

Cation

The first ion in a chemical formula, positive

Anion

The second ion in a chemical formula, negative

Mass

The amount of matter in an object

Length

The distance between two points

Volume

The space occupied by an object

Meniscus

The curve of a liquid in a graduated cylinder

Time

The interval between two events

Temperature

The measure of how hot or cold something is

Density

Mass per volume of a material.

Derived Unit

Two simple units combined.

Groups

Vertical columns on the periodic table (also known as families)

Periods

Horizontal rows on the periodic table

Democritus

Stated that all matter was made up of tiny particles called atoms that could not be broken down into smaller parts.

Atomos

Greek work for “indivisible”