Alkaline earth metal — মৃৎক্ষার ধাতু
Alkaline earth metals are Group 2 elements (Be to Ra) with two valence electrons; they form +2 ions.
Definition
The alkaline earth metals — beryllium, magnesium, calcium, strontium, barium and radium — make up Group 2, each donating its two valence electrons to form +2 ions. They are harder and denser than their Group 1 neighbours and react with water more calmly: calcium hisses gently in cold water, while magnesium needs steam to really get going. Their compounds colour flames — calcium brick-red, strontium crimson — which is why their salts light up fireworks and flares. Life leans on this family: magnesium anchors chlorophyll, calcium builds bones and eggshells.
For example
Light a magnesium ribbon in the lab and it burns with a dazzling white light hard to look at — the same white flash photographers once used and your teacher now shows off yearly.