Essential Reference Sheet for Introductory Chemistry

List of Elements with Their Symbols and Atomic Masses

Overview

This section provides a comprehensive table of chemical elements, including their names, symbols, and atomic masses. Understanding these properties is fundamental for identifying elements, writing chemical formulas, and performing calculations in chemistry.

• Element Name: The official name of the element.

• Symbol: The one- or two-letter abbreviation used to represent the element in chemical equations.

• Atomic Mass: The average mass of an atom of the element, measured in atomic mass units (amu).

Example: Hydrogen (H) has an atomic mass of approximately 1.008 amu, while Carbon (C) has an atomic mass of about 12.01 amu.

Element	Symbol	Atomic Mass (amu)
Hydrogen	H	1.008
Carbon	C	12.01
Oxygen	O	16.00
Nitrogen	N	14.01
Sodium	Na	22.99
Chlorine	Cl	35.45

Common Conversion Factors and Relationships

Overview

Conversion factors are essential for solving chemistry problems involving units. This section summarizes key relationships used in measurements, stoichiometry, and calculations.

• Length: $1\ \text{m} = 100\ \text{cm} = 1000\ \text{mm}$

• Mass: $1\ \text{kg} = 1000\ \text{g}$

• Volume: $1\ \text{L} = 1000\ \text{mL}$

• Avogadro's Number: $1\ \text{mol} = 6.022 \times 10^{23}\ \text{particles}$

• Energy: $1\ \text{cal} = 4.184\ \text{J}$

Example: To convert 250 mL to liters: $250\ \text{mL} \times \frac{1\ \text{L}}{1000\ \text{mL}} = 0.25\ \text{L}$

Selected Key Equations

Overview

This section presents fundamental equations used throughout introductory chemistry, including those for stoichiometry, gas laws, and solution calculations.

• Mole Calculations: $\text{Moles} = \frac{\text{Mass (g)}}{\text{Molar Mass (g/mol)}}$

• Ideal Gas Law: $PV = nRT$

• Concentration: $\text{Molarity} = \frac{\text{Moles of solute}}{\text{Liters of solution}}$

• Dilution: $M_1V_1 = M_2V_2$

• Percent Composition: $\%\ \text{Composition} = \frac{\text{Mass of element}}{\text{Total mass}} \times 100\%$

• Energy Change: $q = mC\Delta T$

Example: To find the number of moles in 18 g of water ($\text{H}_2\text{O}$): $\text{Moles} = \frac{18\ \text{g}}{18.02\ \text{g/mol}} = 1\ \text{mol}$

Mathematical Constants

Overview

Chemistry calculations often require mathematical constants such as pi ($\pi$), Avogadro's number, and the gas constant ($R$). These values are used in equations for energy, gas laws, and molecular calculations.

• Pi ($\pi$): $\pi \approx 3.1416$

• Avogadro's Number ($N_A$): $6.022 \times 10^{23}$

• Gas Constant ($R$): $0.0821\ \text{L} \cdot \text{atm} / \text{mol} \cdot \text{K}$

Example: The ideal gas law uses $R$ to relate pressure, volume, temperature, and moles of gas.

Summary Table: Key Chemistry Constants

Purpose

This table summarizes the most frequently used constants in introductory chemistry, aiding in calculations and problem solving.

Constant	Symbol	Value	Units
Avogadro's Number	$N_A$	$6.022 \times 10^{23}$	particles/mol
Gas Constant	$R$	$0.0821$	L·atm/(mol·K)
Speed of Light	$c$	$3.00 \times 10^8$	m/s
Planck's Constant	$h$	$6.626 \times 10^{-34}$	J·s
Faraday Constant	$F$	$96,485$	C/mol

Application in Introductory Chemistry

Overview

The information provided in these tables and equations is directly relevant to the following chapters: Atoms and Elements, Molecules and Compounds, Chemical Composition, Chemical Reactions, Quantities in Chemical Reactions, Gases, Solutions, Acids and Bases, and Chemical Equilibrium. Mastery of these constants, conversion factors, and equations is essential for success in introductory chemistry courses.