Periodic Table of Elements
Tap any element to see its atomic number, mass, group, period, block and category. Search by name, symbol or number, or filter by category.
Periodic table of the elements
How to read the table
Elements are arranged by atomic number (protons in the nucleus). Rows are periods and columns are groups. Elements in the same group have the same number of valence electrons and behave in a similar way. The metals are on the left and centre, the nonmetals on the right, and metalloids lie along the staircase between them.
Details Calvo shows
Atomic number, symbol, name, atomic mass, group, period, block (s, p, d or f), category, valence electrons for main-group elements, and the approximate number of neutrons in the most common isotope (mass number minus atomic number).
Atomic masses
Masses are standard atomic weights rounded to a few decimal places, as in most textbooks. For radioactive elements the mass is the mass number of the most stable known isotope.
FAQ
How is the periodic table arranged?
By increasing atomic number. Rows are periods and columns are groups with similar chemical properties.
How many elements are there?
118 elements are confirmed and named. Calvo shows all of them.
What are s, p, d and f blocks?
They show which orbital type receives the last electron. Groups 1 and 2 (and helium) are the s-block, groups 13 to 18 the p-block, the transition metals the d-block, and the lanthanides and actinides the f-block.
Why are the lanthanides and actinides shown below?
They fit into periods 6 and 7 but would make the table too wide, so they are shown in two separate rows.
Can I find the molar mass of a compound?
Yes, use the Molar Mass Calculator on Calvo. It uses these same atomic masses.