Ch.2 - Atoms & ElementsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Sections
The Atom
Subatomic Particles
Isotopes
Ions
Atomic Mass
Periodic Table: Classifications
Periodic Table: Group Names
Periodic Table: Representative Elements & Transition Metals
Periodic Table: Element Symbols
Periodic Table: Elemental Forms
Periodic Table: Phases
Periodic Table: Charges
Calculating Molar Mass
Mole Concept
Law of Conservation of Mass
Law of Definite Proportions
Atomic Theory
Law of Multiple Proportions
Millikan Oil Drop Experiment
Rutherford Gold Foil Experiment
Additional Practice
Thomson's Cathode Ray Tube Experiment
The Chadwick Neutron Experiment
Mass Spectrometry
Additional Guides
Periodic table Charges (ignore)
Calculating Molar Mass (ignore)
Calculating Grams to Moles

The atom is composed of 3 subatomic particles: neutrons, protons, and electrons.

The Atom & Subatomic Particles

In terms of size, neutrons are the largest, protons are slightly smaller, and the electrons are the smallest.

Concept #1: The 3 subatomic particles share key differences and similarities in their masses and charges.  

Example #1: Osmium, one of the densest elements on earth, has an actual mass of 190.23 grams. According to the table above, what is its value in terms of atomic mass units?

Practice: According to the table above, how many electrons are required to produce a charge of –2.0 C?

Practice: If the charge and mass of one proton is 1.60218 x 10-19 C and 1.673 x 10-30 g respectively, what is the charge of 378 kg of protons?