(E1PX1)Basic Chemistry Review for Lecture Exam 1

Element

Substance made of one type of atom.

Atom

Smallest unit of an element.

Proton

Positive charge, 1 mass unit, in nucleus.

Neutron

No charge, 1 mass unit, in nucleus.

Electron

Negative charge, negligible mass, orbits nucleus.

Atomic number

Number of protons in an element.

Atomic mass

Total mass of protons and neutrons.

Ion

Charged atom due to electron loss or gain.

Anion

Negatively charged ion (gains electrons).

Cation

Positively charged ion (loses electrons).

Isotope

Atoms of the same element with different neutrons.

Half-life

Time for half of a radioactive isotope to decay.

Chemical reactivity

How an atom interacts with other atoms.

Hydrophilic

Water-loving, polar substances that dissolve in water.

Hydrophobic

Water-fearing, nonpolar substances that do not dissolve.

Cohesion

Attraction between molecules of the same substance.

Adhesion

Attraction between molecules of different substances.

Heat capacity

Energy needed to raise temperature of 1 g by 1°C.

Boiling point

Temperature at which a liquid turns to vapor.

pH

Measure of hydrogen ion concentration in a solution.

Acid

Substance that donates protons (H+).

Base

Substance that accepts protons (H+).

Solvent

Liquid that dissolves solutes to form a solution.

Solute

Substance dissolved in a solvent.

Solution

Homogeneous mixture of solute and solvent.

Chemical bond

Attraction between atoms that forms molecules.

Electron shell

Region around nucleus where electrons reside.

Electron configuration

Arrangement of electrons in an atom's shells.