Naturally occurring Boron is made up of 19.9% \(^{10}\)B and 80.1% \(^{11}\)B. The relative atomic mass of Boron is

The number of shared pair of electrons in a molecule of methane is 

Isotopes of the same element have similar chemical properties because they have the same number of

Which of the following household liquids would be effective in treating someone with too much acid in the stomach?

The percentage by mass of Oxygen in MgSO\(_4\).7H\(_2\)O is [ M\(_r\) of MgSO\(_4\).7H\(_2\)O = 246 ]