HesapHanem

Element Properties Lookup

Type an element symbol, name or atomic number to look it up.

How it is calculated

This is a lookup, not a formula. The tool checks what you type against a table of all 118 elements and returns the matching row: name, symbol, atomic number, standard atomic mass (to three decimals, in atomic mass units u), group and period. You can search by chemical symbol (Fe), by element name (iron, or the Turkish demir, and the spellings Aluminum, Sulphur and Cesium also work) or by atomic number (26). Case and surrounding spaces do not matter. A decimal such as 26.0 gives no result. An element with no stable isotope shows the mass number of its longest-lived or best-known isotope in square brackets. Lanthanides and actinides show a dash for the group, because they sit in the f-block; lutetium and lawrencium are shown in group 3.

Worked example

Type Fe. The tool finds the row for iron and returns: name Iron, symbol Fe, atomic number 26, atomic mass 55.845 u, group 8 and period 4. Typing iron or 26 returns the same row. You can use the mass directly in a molar-mass calculation, for example one mole of iron atoms weighs about 55.845 g. Typing Tc shows a bracketed mass, [98] u, because technetium has no stable isotope.

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Common mistakes

  • Reading a bracketed mass as a measured average. [98] u for technetium is the mass number of one isotope.
  • Typing the atomic mass or a decimal like 26.0 in place of the atomic number. The number must be a plain whole number such as 26.
  • Treating the atomic mass as a mass number. 55.845 u is a weighted average of the natural isotopes, not a whole number of nucleons.
  • Expecting a group number for the f-block. Charts differ on where lanthanum and actinium go, and a dash means this table gives those rows no group.

About this calculator

Every entry on the periodic table carries a fixed set of identifying data: its atomic number (protons in the nucleus, which fixes the element's identity), its standard atomic mass (a weighted average of its naturally occurring isotopes, in atomic mass units), and its position by group (vertical column, elements sharing valence-electron structure) and period (horizontal row, tied to electron shell count) — the arrangement that gives the table its recurring chemical patterns.

This tool looks up all 118 elements by chemical symbol, name or atomic number and returns its atomic mass, group, and period in one search, saving a scan across a printed or PDF periodic table. Chemistry students doing homework, teachers building quizzes, and anyone double-checking a stoichiometry calculation use it as a faster reference than flipping through a textbook appendix.

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Comments (1)

  • Editorial team

    Use the group, not the mass, to find an element's chemical relatives. Hg returns group 12 and period 6, which places it with zinc and cadmium, and its mass of 200.592 u adds nothing to that comparison. You can also type an atomic number, and the spellings aluminum, sulphur and cesium are recognised. La shows a dash for the group. Which property would you like to see added to this table?

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