Alkaline Earth Metals: What Most Textbooks Rarely Mention

(mostly adapted from Emsley, John. Nature’s Building Blocks.`Oxford. 2003)

Beryllium, Be Be is very toxic. Inhale it in sufficient amounts or in smaller doses but consistently over a prolonged period and you will get lung disease. Ingest it and it is still a poison because Be imitates Mg⁺² and renders vital enzymes useless.

Magnesium, Mg In animals, Mg regulates movement through cell membranes; it is a cofactor of >100 enzymes; it helps assemble proteins and plays a role in DNA replication. In plants there is a Mg atom at the core of every chlorophyll molecule.

Although strips of Mg burn easily and give off a white, dazzling light, thick tubes of the stuff do not ignite easily and are safe enough for making very light bicycle frames.

Calcium, Ca Bone is made up of a calcium compound: Ca₅(PO₄)₃OH. But Ca⁺² is involved in many other vital functions:

(1) It helps binds cells together.

(2) It helps muscles contract and nerve impulses to flow

(3) It controls cell divisions.

(4) It facilitates blood clots.

(5) It triggers hormone release.

An American, Conrad Johnston, used 60 pairs of twins in a study. He gave one twin from each pair a Ca⁺² tablet every day for 3 years and found bone growth to be much faster than in the twin who did not receive the supplement.

Strontium, Sr A radioactive isotope of strontium,⁹⁰Sr, is a powerful b emitter and can damage dividing cells. It ends up in our skeletons and teeth when it is released into the atmosphere by either above-ground nuclear tests (now banned) or nuclear accidents.

Barium, Ba Ba⁺² is highly poisonous. Fortunately, some barium salts such as barium sulphate are insoluble in both water and stomach acid(unlike barium carbonate, which dissolves in the latter) and can be used in medicine. Since the salt is opaque to X-rays, it can show the outline of the intestines, which would otherwise not be seen.

Radium, Ra In the early 20^th century, some women who worked on a daily basis with radium became so contaminated with this powerful a- particle emitter that, just like the dials on the watches they painted, their faces and other body parts glowed in the dark.