A sample of oxygen contains two isotopes of oxygen with masses 16 u and 18 u respectively. The proportion of these isotopes in the sample is 3 : 1. What will be the average atomic mass of oxygen in this sample?
17·5 u
17 u
16 u16·5 u
16·5 u
For election to the Lok Sabha, a nomination paper can be filed by
Miscellaneous · Easy
In a month if the seventh day is three days earlier than Saturday,then the nineteenth day of the month will be a
Miscellaneous · Easy
Which among the following events happened earliest ?
Miscellaneous · Easy
An 80-litre solution of alcohol and water has 75% alcohol. How much water (in litres) must be added to bring down the concentration of alcohol to 60%?
Miscellaneous · Easy