Tap an element for its details. Pinch, scroll or use + and − to zoom, and drag to move around.
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Showing 118 of 118 elements
Elements by Type
Alkali metals
6 Elements
Soft, very reactive metals in group 1. Hydrogen sits above them but is not one.
Alkaline earth metals
6 Elements
Reactive metals in group 2, a little less reactive than the alkali metals.
Transition metals
38 Elements
The middle of the table, including most everyday metals like iron, copper, silver and gold.
Post-transition metals
11 Elements
Softer metals to the right of the transition metals, such as aluminum, tin and lead.
Metalloids
7 Elements
Between the metals and the nonmetals, with traits of both. Silicon is the best known.
Nonmetals
7 Elements
Hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur and selenium, the building blocks of living things.
Halogens
6 Elements
Very reactive nonmetals in group 17 that form salts with metals.
Noble gases
7 Elements
The group 18 gases, which barely react with anything.
Lanthanides
15 Elements
Elements 57–71, the first of the two rows printed below the table.
Actinides
15 Elements
Elements 89–103, the second row below the table. All are radioactive.
No elements match these filters.
Every element in one table you can zoom, filter and tap. The list under the table groups the
elements by type, and each one opens the same detail card. Values come from PubChem.
How to Read This Table
Group numbers run across the top (1–18) and period numbers down the left side (1–7).
The small number in a tile’s corner is the atomic number: the number of protons in one atom
of the element.
Atomic mass is the average mass of the element’s atoms in atomic mass units (u), rounded to
three decimal places. It is also the element’s molar mass in grams per mole.
A mass in [brackets] belongs to an element with no stable isotopes. The number is the mass
number of its longest-lived isotope, not an average.
The color is the element’s type, which predicts much of how it behaves. The chips under the
table name each color and filter by it.
The lanthanides (57–71) and actinides (89–103) sit in the two rows under the table so it
fits on a page. They belong in periods 6 and 7, where the 57–71 and 89–103 markers are.
What the Detail Card Shows
State at room temperature is the element’s state at about 20 °C. For the heaviest elements
it is a prediction, since only a few atoms of them have ever been made.
Melting and boiling points are in degrees Celsius, with kelvin underneath.
Density is in g/cm³, or in g/L for gases.
Electronegativity is on the Pauling scale: how strongly an atom pulls shared electrons toward
itself.
Ionization energy is the energy needed to remove one electron from a single atom, in
electronvolts (eV).
Common Mistakes
Mixing up atomic number and atomic mass. The atomic number counts protons and is always a
whole number; the atomic mass is an average and has decimals.
Mixing up groups and periods. Groups are the columns, and elements in the same group behave
alike. Periods are the rows.
Counting hydrogen as an alkali metal. It sits at the top of group 1, but it is a nonmetal and
a gas.
Frequently Asked Questions
Why are some atomic masses in brackets?
Those elements have no stable isotopes, so they have no natural average mass. The bracketed number is the mass number of the isotope that lasts longest.
Is atomic mass the same as molar mass?
Numerically, yes. An element with an atomic mass of 12.011 u has a molar mass of 12.011 grams per mole, which is the number you use in stoichiometry.
How precise are these masses?
They are rounded to three decimal places, enough for most chemistry classes. If your course uses a different table, use the values your teacher gives you so your answers match.
Where are the group and period numbers?
Group numbers run across the top of the table and period numbers down its left side. Tap any element to see its group, period, block and electron configuration.
Why is polonium listed as a metalloid?
Because PubChem, this page's source, classifies it that way. Some textbooks call polonium a post-transition metal instead, since it behaves like both; if your class's table differs, go with your class.
Why are two rows printed below the table?
The lanthanides and actinides belong in periods 6 and 7, but putting them in line would make the table 32 columns wide. Printing them underneath keeps it readable.