What is the atomic number of Radium?

Radium has atomic number 88, which means a neutral atom has 88 protons and 88 electrons.

What is the chemical symbol for Radium?

The chemical symbol for Radium is Ra.

What category is Radium in?

Radium is classified as a alkaline earth metal and sits in period 7 of the periodic table.

Element 88

Radium (Ra)

Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen on exposure to air.

Atomic Number

Atomic Mass

226 u

Period

Group

Group 2: alkaline earth metals

Phase

solid

Density

5.5 g/cm3

Electron Shells

2, 8, 18, 32, 18, 8, 2

Atomic Structure

Protons: 88. Electrons: 88. Neutrons: Varies by isotope.

Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s²

Why Radium Matters

Radium helps connect atomic number 88, alkaline earth metal behavior, period 7 trends, and electron shell structure. Its solid phase, atomic mass of 226 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² make it useful for comparing bonding patterns across the periodic table.

Discovery and Occurrence

Radium was discovered 1898 by Marie Curie, Pierre Curie. Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen on exposure to air.

Safety and Handling Context

Radium has radioactive isotopes or is commonly discussed with radioactive materials. Use this page as an educational reference; real samples require qualified supervision and controlled handling.

Related Elements

Frequently Asked Questions

What is the atomic number of Radium?: Radium has atomic number 88, which means a neutral atom has 88 protons and 88 electrons.
What is the chemical symbol for Radium?: The chemical symbol for Radium is Ra.
What category is Radium in?: Radium is classified as a alkaline earth metal and sits in period 7 of the periodic table.

Explore Radium in 3D

Use the interactive table above to rotate atomic models, compare periodic trends, and move from Radium to neighboring elements without losing your place.