Question

Give the names of the elements present in:

chalk

Answer 1

Chalk $\left({\mathrm{CaCO}}_3\right)$ is a compound.

Compound: A compound is a pure substance in which elements combine chemically in a fixed composition to give a compound.

• They can be broken down into elements that make up the compound by using chemical or electrochemical methods.
• Example: Water $\left({\mathrm{H}}_2\mathrm{O}\right)$, Common salt i.e. Sodium chloride $\left(\mathrm{NaCl}\right)$

To find out the elements present in Chalk:

Step-1: Write the chemical formula of the compound

• Chalk is a compound with chemical formula ${\mathrm{CaCO}}_3$ i.e.; Calcium carbonate

Step-2: Identify the elements present in the compound from their chemical symbols.

S.No	Symbol of the element	Name of the element
1	$\mathrm{Ca}$	Calcium
2	$\mathrm{C}$	Carbon
3	$\mathrm{O}$	Oxygen

Element: An element is a pure substance that cannot be split into simpler substances.

• Example: Hydrogen $\left({\mathrm{H}}_{}\right)$, Copper $\left(\mathrm{Cu}\right)$ etc.