Question

Match the statements in column A with those in column B.

Column 1	Column 2
A carbonate of sodium.	Copper
An acid containing sulphur.	Helium
A chemically inactive element.	Molecule
An element which is generally good conductor of electricity.	Sulphuric acid
The smallest unit of matter, always has an independent existence.	Sodium carbonate
An oxide of lead	$\mathrm{CaS}$
A sulphide of calcium.	$\mathrm{PbO}$
Latin name of silver	Atom
The smallest particle of an element, which takes part in a chemical reaction	Molecule
The smallest unit of a pure substance, which always exists independently.	Argentum
A solid which settles at the base, when a suspension is allowed to stand in a beaker.	Sublimate
The condensation of vapors of pure liquid during the process of distillation.	Filtrate
A solid left on the filter paper, during the process of filtration.	Sediment
A solid formed from its hot vapor.	Pure substance
A substance having only one kind of particles.	Distillate

Answer 1

• A carbonate of sodium - Sodium carbonate. The formula of carbonate is ${\mathrm{CO}}_3^{2-}$and that of calcium ion is${\mathrm{Na}}^{+}$. Thus the formula of carbonate of sodium is${\mathrm{Na}}_2{\mathrm{CO}}_3$.
• An acid containing sulphur - Sulphuric acid. Acids are those substances that donate ${\mathrm{H}}^{+}$ ions in their aqueous solution. The chemical formula of Sulphuric acid is${\mathrm{H}}_2{\mathrm{SO}}_4$, on dissolving in water gives $2{\mathrm{H}}^{+}\mathrm{and}{\mathrm{SO}}_4^{2-}$ions.
• A chemically inactive element - He. Due to the presence of a filled valence shell, noble gases are considered inert elements.
• An element that is generally a good conductor of electricity - Copper. Metals are the elements that have excess electrons due to which metals are good conductors of electricity. Copper is a metal, that is a good conductor of electricity.
• The smallest unit of matter, always has an independent existence - Molecule. A molecule is the smallest particle of a material (element or compound) with the properties of that substance and the ability to exist in its free state.
• An oxide of lead - $\mathrm{PbO}$. The symbol of lead and oxygen is$\mathrm{Pb}\mathrm{and}\mathrm{O}$, the valency of both of them is $+2\mathrm{and}-2$. By the criss-cross method, the oxide of lead is $\mathrm{PbO}$.
• A sulphide of calcium - $\mathrm{CaS}$. The symbol of lead and oxygen is$\mathrm{Ca}\mathrm{and}\mathrm{S}$, the valency of both of them is $+2\mathrm{and}-2$. By the criss-cross method, the oxide of lead is $\mathrm{CaS}$.
• Latin name of silver - Argentum. Earlier, Silver is called Argentum. Its chemical symbol is also taken from its Latin name i.e., Ag.
• The smallest particle of an element, which takes part in a chemical reaction - atom. Atom is the smallest representation of an element.
• The smallest unit of a pure substance, which always exists independently - molecule. Atoms generally exist in two forms - as molecules or as ions.
  A molecule is the smallest particle of a material (element or compound) with the properties of that substance and the ability to exist in its free state.
• A solid which settles at the base, when a suspension is allowed to stand in a beaker - sediment. Sedimentation is the process of settling down the heavier components of a mixture. For example, when a sand-in-water mixture is allowed to stand undisturbed for a period of time, and settle.
• The condensation of vapors of pure liquid during the process of distillation - distillate. The process of selective boiling and condensing the selective component of a solution is known as distillation.
• A solid left on the filter paper, during the process of filtration - Filtrate. Filtration is technically defined as the process of separating suspended solid matter from a liquid by passing it through the pores of a membrane known as a filter paper. Filtration examples include a mixture of chalk and water, which on passing through a filter paper, chalk will remain on the filter paper as filtrate and water pass through it.
• A solid formed from its hot vapor - sublimate. Sublimation is a process of converting solids directly into vapors without passing through the liquid state.
• A substance having only one kind of particle - pure substances. Pure substances are those substances that are made up of only one kind of particle (atoms or molecules). Pure substances are either an element or a compound. For example - Gold, Silver, Water, Carbon dioxide, etc.