Questions

Endorphins are called pain controlling chemicals in the body.

The troposphere is the lowest layer of the atmosphere and where most clouds are. That means all weather is in the troposphere. Almost all weather occurs in the Troposphere, basically, the lowest layer that goes up to about 10 - 15 kms.

The capacity of a water heater is measured in Gallons or Liters. In the USA, it is measured in Gallons and in India, we measure it in Liters.

Hence, if the capacity of the water heater is 15 gallons or 15 liters, then it says that it can hold 15 gallons or 15 liters of water.

Australia won the 1987/88 Reliance World Cup against England held in Kolkata, India.

Nitrogen (N2) forms Three Covalent Bonds to become stable.

Here the Atmomic Number of Nitrogen is 7. Because there are 2 electrons in the first orbital and 5 in the second and you still have space for 3 more. So it shares, 3 to get the stable octet. Therefore, there are 3 covalent bonds in N2.