General Chemistry
Electron configuration, atomic mass, molar mass, percent composition, and bond order, plus periodic-trend tools like electronegativity and effective nuclear charge, make up the foundational chemistry subcategory most introductory courses draw from first.
Calculators & Tools
Combined Gas Law Calculator
The Combined Gas Law Calculator solves for any unknown pressure, volume, or temperature when a gas changes from one set of conditions to another. It combines Boyle's Law, Charles's Law, and Gay-Lussac's Law into a single equation relating the initial and final states of an ideal gas. Use it for chemistry coursework, laboratory gas calculations, and industrial process engineering problems involving gas state changes.
Atom Calculator
The Atom Calculator works out the number of protons, neutrons, and electrons in any atom or ion. Select an element from the periodic table or enter the atomic number and mass number manually, then set the ionic charge to find the full subatomic particle breakdown, approximate atom mass in atomic mass units, and electron configuration.
Percent Ionic Character Calculator
The Percent Ionic Character Calculator determines how ionic a chemical bond is using two methods. The dipole moment method compares a bond's measured dipole moment to the theoretical dipole moment for a fully ionic bond of the same length. The electronegativity method estimates ionic character from Pauling's empirical formula. Both methods quantify where a real bond falls on the spectrum between pure covalent and pure ionic.
Atomic Mass Calculator
The Atomic Mass Calculator computes the mass of a specific atom or isotope in atomic mass units (amu) and kilograms from its proton and neutron counts. Select a common element to auto-fill the proton count or enter values manually, then compare the calculated isotope mass against the periodic table standard atomic weight to see how natural isotope abundance changes the average.
Average Atomic Mass Calculator
The Average Atomic Mass Calculator computes the periodic-table-style weighted average mass of an element from the masses and natural abundances of its isotopes. Enter two or more isotopes with their mass and percent abundance, or use solve mode to find a missing abundance when the target average mass is known. Quick presets are included for chlorine, copper, boron, bromine, magnesium, and lithium.
pKa Calculator
The pKa Calculator converts between the acid dissociation constant (Ka) and pKa, and separately solves the Henderson-Hasselbalch equation to find buffer solution pH from pKa and the conjugate base to acid concentration ratio. Quick presets are included for common weak acids like acetic acid, phosphoric acid, and ammonium.
Electronegativity Calculator
The Electronegativity Calculator finds the electronegativity difference (Δχ) between any two elements using Pauling scale values, classifies the resulting bond as nonpolar covalent, polar covalent, or ionic, and estimates the percent ionic character using Pauling's empirical formula. Select any two of 40 common elements to see the dipole direction and full calculation breakdown.
Electron Configuration Calculator
The Electron Configuration Calculator generates the full and noble gas shorthand electron configuration for any element from hydrogen to lead, including ions. It applies the aufbau principle, accounts for known exceptions like chromium and copper, and displays an orbital box diagram following Hund's rule along with the valence electron count.
Percent Composition Calculator
The Percent Composition Calculator computes the mass percentage of each element in a chemical compound from its formula. In reverse, the empirical formula finder mode takes mass percentages for each element and works out the simplest whole-number ratio formula. Both modes update results automatically as you type.
Chemical Name Calculator
The Chemical Name Calculator converts between chemical formulas and their systematic names. Formula-to-name mode recognizes common ionic compounds (with Roman numeral notation for multivalent metals), binary covalent compounds (using Greek number prefixes), and common acids. Name-to-formula mode lets you select a cation and anion to build a charge-balanced ionic formula automatically.
Molar Mass Calculator
The Molar Mass Calculator computes the molar mass of any chemical compound in grams per mole from its formula. It supports nested parentheses (Al2(SO4)3), hydrates (CuSO4.5H2O), and returns a full per-element breakdown showing each element's contribution and percent of total mass.
Bond Order Calculator
The Bond Order Calculator finds the bond order of a molecule using two methods. Molecular orbital theory mode computes (bonding electrons minus antibonding electrons) divided by two from MO diagram electron counts. Resonance mode averages total bond count across all valid resonance structures for species like ozone, carbonate, and nitrate where bond order is fractional. Quick presets are included for common diatomics and resonance-stabilized ions.
Effective Nuclear Charge Calculator
The Effective Nuclear Charge Calculator computes Zeff for any electron in any element from hydrogen to lead using Slater's rules. Select an element or enter an atomic number, choose the electron subshell of interest, and the calculator auto-generates the full aufbau electron configuration, groups electrons according to Slater's shielding rules, and shows a complete contribution breakdown by shell.