Calculate The Atomic Radius in Cm for The Following

Atomic radius is a fundamental property of elements that determines their size and reactivity. This calculator helps you determine the atomic radius in centimeters for any element by using known atomic radius values or calculating from other properties.

What is atomic radius?

The atomic radius of an element is half the distance between the nuclei of two identical atoms bonded together. It's typically measured in picometers (pm) or centimeters (cm) and varies depending on the element's position in the periodic table.

Atomic radius is important because it influences:

Chemical reactivity
Bond formation
Crystal structure
Physical properties like melting point and boiling point

Note: Atomic radius values can vary depending on the measurement method (covalent, metallic, or van der Waals) and the specific conditions under which they were measured.

How to calculate atomic radius

The atomic radius can be calculated using several methods, including:

Direct measurement using X-ray crystallography or electron microscopy
Calculation from known atomic radius values
Estimation using periodic trends

Formula: Atomic radius (cm) = (Atomic radius in pm) × 10^-10

Where 1 picometer (pm) = 10^-12 meters

For most practical purposes, atomic radius values are available in reference tables and databases. The calculator on this page uses standard atomic radius values for common elements.

Atomic radius trends in the periodic table

Atomic radius follows predictable trends across the periodic table:

Increases from top to bottom in a group (due to additional electron shells)
Decreases from left to right across a period (due to increasing nuclear charge)
Generally larger for metals than non-metals

Element	Atomic Radius (pm)	Atomic Radius (cm)
Hydrogen (H)	53	5.3 × 10^-11
Helium (He)	31	3.1 × 10^-11
Lithium (Li)	167	1.67 × 10^-9
Beryllium (Be)	112	1.12 × 10^-9
Boron (B)	87	8.7 × 10^-10

Example calculations

Example 1: Calculating atomic radius of hydrogen

Given:

Atomic radius of hydrogen = 53 pm

Calculation:

Atomic radius (cm) = 53 pm × 10^-10 = 5.3 × 10^-11 cm

Result: The atomic radius of hydrogen is 5.3 × 10^-11 cm.

Example 2: Calculating atomic radius of lithium

Given:

Atomic radius of lithium = 167 pm

Calculation:

Atomic radius (cm) = 167 pm × 10^-10 = 1.67 × 10^-8 cm

Result: The atomic radius of lithium is 1.67 × 10^-8 cm.

FAQ

What is the difference between atomic radius and covalent radius?

Atomic radius refers to the distance from the nucleus to the outermost electron shell, while covalent radius specifically refers to the distance between the nuclei of two identical atoms bonded together by a covalent bond.

Why do atomic radii vary between different elements?

Atomic radii vary due to differences in nuclear charge, electron configuration, and the number of electron shells. Elements with more protons have a stronger nuclear charge, pulling electrons closer, while elements with more electron shells have larger radii.

How accurate are atomic radius measurements?

Atomic radius measurements are generally accurate to within a few picometers, with modern techniques like X-ray crystallography providing precise values. However, some variations can occur depending on the measurement method and conditions.