Questions

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

Salivary glands of man are 3 pairs = 6. They are one pair of parotid glands, one pair of sub-maxillary or sub-mandibular glands and one pair of sub-lingual glands.

Shipment movement information is captured each time a tracking label is scanned in the UPS delivery system. There may be several days between scans if the shipment is going cross-country or moving between countries.

Destination Scan: The shipment has arrived at the local UPS facility responsible for final delivery.

Arrival Scan: The shipment has arrived at a UPS facility.

Departure Scan: The shipment has departed a UPS facility and is on its way to the next UPS facility.

Origin Scan: UPS has received the shipment.

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

It was on February 28th, 1928 that CV Raman announced  his discovery of New radiation-subsequently named the Raman Effect- that won him the Noble prize.

Vikram Sarabhai Space Centre is located at Thiruvananthapuram, Kerala.

• This is the lead centre of ISRO responsible for the design and development of launch vehicle technology focusing on rocket and space vehicles for India's satellite programme.