GROUP 2: ALKALINE EARTH METALS

Alkaline Earth Metals Overview

Also known as: Beryllium family

Group Members: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra)

Common Properties: All have two valence electrons, form +2 ions, reactive but less so than alkali metals, silvery-white, shiny

Be

Beryllium

Toxic
Atomic Number 4
Atomic Mass 9.01 u
Electron Config [He] 2s²
Common Ions Be²⁺
Melting Point 1287°C
Density 1.85 g/cm³
Beryllium is transparent to X-rays and was used in the first X-ray tubes!

Properties: Light, stiff, toxic, gray, excellent thermal conductor

Applications: Aerospace components, X-ray windows, nuclear reactors, electronics

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Mg

Magnesium

Flammable
Atomic Number 12
Atomic Mass 24.31 u
Electron Config [Ne] 3s²
Common Ions Mg²⁺
Melting Point 650°C
Density 1.74 g/cm³
Magnesium burns with an intense white light and is used in fireworks and flares!

Properties: Light, strong, silvery-white, flammable, essential for life

Applications: Alloys, fireworks, dietary supplements, cars, laptops

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Ca

Calcium

Essential
Atomic Number 20
Atomic Mass 40.08 u
Electron Config [Ar] 4s²
Common Ions Ca²⁺
Melting Point 842°C
Density 1.55 g/cm³
Calcium is the 5th most abundant element in Earth's crust and makes up about 4% of our bones!

Properties: Soft, silvery-white, reactive, essential for bones and teeth

Applications: Construction materials, dietary supplements, cheese making, plaster

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Sr

Strontium

Colorful
Atomic Number 38
Atomic Mass 87.62 u
Electron Config [Kr] 5s²
Common Ions Sr²⁺
Melting Point 777°C
Density 2.64 g/cm³
Strontium gives fireworks their brilliant red color and is used in "glow in the dark" paints!

Properties: Soft, silvery-white, reactive, produces red flame

Applications: Fireworks, glow-in-dark paints, toothpaste for sensitive teeth, cancer treatment

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Ba

Barium

Toxic
Atomic Number 56
Atomic Mass 137.33 u
Electron Config [Xe] 6s²
Common Ions Ba²⁺
Melting Point 727°C
Density 3.51 g/cm³
Barium sulfate is used in "barium meals" for X-rays because it's opaque to radiation!

Properties: Soft, silvery-white, reactive, toxic, produces green flame

Applications: X-ray contrast medium, fireworks, glassmaking, rat poison

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Ra

Radium

Radioactive
Atomic Number 88
Atomic Mass 226 u
Electron Config [Rn] 7s²
Common Ions Ra²⁺
Half-life 1600 years
Stability Radioactive
Radium was once used in glow-in-the-dark watch dials before its radioactivity was understood!

Properties: Radioactive, silvery-white, glows in the dark, highly toxic

Applications: Cancer treatment, industrial radiography, scientific research

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