Catadromous fish migrates from

Which one of the following statements is wrong?

Which of the following equations is a balanced one?

With a standard rectangular bar magnet,the time period of a vibration magnetometer is $4 ~s$. The bar magnet is cut parallel to its length into four equal pieces. The time period of the vibration magnetometer when one piece is used (in seconds) (bar magnet breadth is small) is

In which of the following pairs,the central atoms have the same number of lone pairs of electrons?

Which of the following is not correct regarding the properties of ionic compounds?