Chem Term 3

Chemical symbols

One- or two-letter abbreviations representing chemical elements.

Subatomic particles

Protons, neutrons, and electrons that make up an atom.

Proton

Positive (+1) charge, relative mass of 1, located in the nucleus.

Neutron

Neutral (0) charge, relative mass of 1, located in the nucleus.

Electron

Negative (-1) charge, negligible mass (~1/1800), located in electron shells.

Atomic number (Z)

The number of protons in the nucleus of an atom.

Mass number (A)

The total number of protons and neutrons in an atom's nucleus.

Periodic table organization

Organized in order of increasing atomic number.

Periodic table groups

Vertical columns indicating the number of valence electrons.

Periodic table periods

Horizontal rows indicating the number of occupied electron shells.

Bohr model

Model of the atom with a nucleus surrounded by electrons in specific energy levels.

Valence electrons

Electrons located in the outermost occupied shell of an atom.

Physical properties of metals

Shiny, malleable, ductile, and good conductors of heat and electricity.

Physical properties of non-metals

Dull, brittle, and poor conductors of heat and electricity.

Law of Conservation of Matter

Matter cannot be created or destroyed in a chemical reaction.

Evidence of a chemical reaction

Color change, temperature change, gas production, precipitate formation, or light emission.

Physical change vs. chemical reaction

Physical changes alter state/appearance; chemical reactions create entirely new substances.

State symbol (aq)

Aqueous, meaning the substance is dissolved in water.

Synthesis reaction

Two or more reactants combine to form a single product.

Decomposition reaction

A single reactant breaks down into two or more simpler products.

Single displacement reaction

One element replaces another element in a compound.

Double displacement reaction

Ions of two compounds exchange places to form two new compounds.

Acid-base neutralization

An acid and a base react to produce salt and water.

Reaction rate

The speed at which reactants are converted into products.

Collision theory

Particles must collide with sufficient energy and correct orientation to react.

Activation energy

The minimum energy required for colliding particles to successfully react.

Effect of temperature on reaction rate

Increases rate by giving particles more kinetic energy, causing more frequent, energetic collisions.

Effect of concentration on reaction rate

Increases rate by putting more particles in a space, increasing collision frequency.

Effect of surface area on reaction rate

Increases rate by exposing more reactant particles to collisions.

Catalyst

Speeds up a reaction by providing an alternative pathway with lower activation energy.