(N/A) $Beryllium$ is used in the manufacture of alloys. $Copper-beryllium$ alloys are used in the preparation of high-strength springs.
Metallic $beryllium$ is used for making windows of $X$-ray tubes. $Magnesium$ forms alloys with $aluminium$,$zinc$,$manganese$,and $tin$.
$Magnesium-aluminium$ alloys,being light in mass,are used in aircraft construction. $Magnesium$ (powder and ribbon) is used in flash powders and bulbs,incendiary bombs,and signals.
$A$ suspension of $magnesium$ $hydroxide$ in water (called $milk$ $of$ $magnesia$) is used as an antacid in medicine. $Magnesium$ $carbonate$ is an ingredient of toothpaste.
$Calcium$ is used in the extraction of metals from oxides which are difficult to reduce with carbon. $Calcium$ and $barium$ metals,owing to their reactivity with oxygen and nitrogen at elevated temperatures,have often been used to remove air from vacuum tubes.
$Radium$ salts are used in radiotherapy,for example,in the treatment of cancer.