Science Final Exam

Democritus

Thought matter could not be created nor destroyed.

Aristotle

Modified an earlier theory that matter was made of four elements: earth, fire, water, and air; he was incorrect.

John Dalton

Proposed several ideas including that all matter is made of atoms.

JJ Thompson

Discovered the electron.

Ernest Rutherford

Conducted the gold foil experiment, leading to the discovery of the atomic nucleus.

Chadwick

Discovered the neutron, contributing to the understanding of atomic structure.

Structure of an atom

Consists of a central nucleus made of protons and neutrons, surrounded by a cloud of electrons at specific energy levels.

Protons

Have a positive charge.

Neutrons

Have a neutral charge.

Electrons

Have a negative charge.

Atomic number

The number of protons in an atom.

Mass number

The total number of protons and neutrons in an atom.

Isotope

When the number of protons and neutrons in an atom are not equal.

Periodic Table Organization

Arranged in order of increasing atomic number with 7 periods and 18 groups.

Alkali metals

Shiny, soft, and the most reactive family on the periodic table.

Covalent bond

A bond formed by the sharing of electrons.

Ionic bond

A bond formed by the transfer of electrons.

Physical change

A change that affects form but not chemical composition; reversible with no new substances formed.

Chemical change

A change that results in the formation of one or more new substances; usually irreversible.

Photosynthesis

Process where 6CO2 + 6H2O + light energy produces C6H12O6 + 6O2.

Cellular respiration

Process where C6H12O6 + 6O2 produces 6CO2 + 6H2O + ATP.

Light-dependent reaction

Occurs in the chloroplast; uses sunlight to produce oxygen and ATP.

Calvin cycle

Occurs in the stroma of chloroplasts, converting CO2 and ATP into glucose.

Glycolysis

The first step in cellular respiration that converts glucose into pyruvic acid and produces ATP.

Krebs Cycle

Processes pyruvic acid to produce CO2 and chemical energy.

Electron Transport System (ETS)

Uses oxygen and chemical energy to produce water and ATP.