Limewater is turned milky by : 1) CO 2) CO₂ 3) 02 4) 03

The incomplete burning of petrol and diesel produces : 1) nitric oxide 2) nitrogen dioxide 3) carbon dioxide 4) carbon monoxide

The elements present in urea are : 1) C, H, O 2) C, N, O 3) C, H, N 4) C, H, N, O

A mixture of sand and naphthalene can be separated by : 1) sublimation 2) distillation. 3) chromatography 4) fractional distillation

The poorest conductor of heat among the following is : 1) copper 2) lead 3) mercury 4) zinc

The vitamin which is effective in blood clotting is : 1) vitamin A 2) vitamin B 3) vitamin D 4) vitamin K

The female sex hormone is : 1) estrogen 2) androgen 3) insulin 4) oxytocin

The Nobel Prize for developing treatment of Parkinson’s disease was given to : 1) Arvid Carlsson 2) John F. Enders 3) Robert B. Laughlin 4) Walter Kohn

The sensitive area of the human tongue to bitterness is : 1) tip 2) middle part 3) posterior part 4) edge

The malfunctioning of thyroid gland is due to the deficiency of : 1) vitamin A 2) calcium 3) iodine 4) iron