Naphthalene is derived from a kind of naphtha which is a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar.

Correct Option: A

Naphthalene is derived from a kind of naphtha which is a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar.

Lignite, often referred to as brown coal, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal. It has a carbon content of around 25-35%.

Correct Option: D

Lignite, often referred to as brown coal, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal. It has a carbon content of around 25-35%.

In the first edition of the Guidelines for Drinking Water Quality, published in 1984, a guideline value of 1.0 mg/litre was established for copper, based on its laundry and other staining properties.

Correct Option: C

In the first edition of the Guidelines for Drinking Water Quality, published in 1984, a guideline value of 1.0 mg/litre was established for copper, based on its laundry and other staining properties.

Seventy percent of bone consists of hydroxyapatite, a calcium phosphate mineral (known as bone mineral). Tooth enamel is composed of almost ninety percent hydroxylapatite.

Correct Option: A

Seventy percent of bone consists of hydroxyapatite, a calcium phosphate mineral (known as bone mineral). Tooth enamel is composed of almost ninety percent hydroxylapatite.

Brine is a solution of salt in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% up to about 26%. Other levels of concentration are called in different names.

Correct Option: A

Brine is a solution of salt in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% up to about 26%. Other levels of concentration are called in different names.