Uses of Calcium (Ca) in Everyday Life

Calcium at work around you

Every use below comes straight from the full Calcium study page, where each point also carries the chemistry behind it and an exam-style question. Skim the list here; open the full page when revision time comes.

Uses of Calcium in the study notes

• Cement and concrete — limestone roasted into clinker binds every structure from village pillars to the Padma Bridge, and lime mortar has plastered Bengali homes for centuries.
• Bone and teeth health — hydroxyapatite, a calcium phosphate, is the mineral of your skeleton, topped up by milk, small fish (mola, dhela) eaten with bones, eggshells and calcium tablets.
• Plaster of Paris and gypsum board — calcium sulfate hemihydrate ($\mathrm{CaSO_{4}}$·½$\mathrm{H_{2}O}$) sets into the cast that heals a broken arm and into the panels of modern ceilings.
• Slaked lime $\mathrm{Ca(OH)_{2}}$ whitewashes village walls before festivals and corrects acidic farm soil, while bleaching powder born from lime disinfects water.

Where you meet it

• Eggshells, snail shells and seashells are nearly pure $\mathrm{CaCO_{3}}$ — drip vinegar on one and watch it fizz as carbon dioxide escapes.
• A stick of blackboard chalk is compressed calcium carbonate — and so is the antacid tablet that settles a sour stomach.
• Milk, yogurt, small fish eaten with their bones and leafy greens are the everyday calcium sources of a Bengali plate.