Actually by swimming a person can easily burn more than 450 calories upto 920 calories per an hour. So, burn less than 400 calories per hour is not correct regarding swimming.
A sentence has been given in Direct/Indirect Speech. Out of the four given alternatives, select the one which best expresses the same sentencein Indirect/Direct Speech.
Ionisation energy is the energy required to remove one mole of electrons from one mole of gaseous atoms. Atoms are more stable when they have full valence shells.
The ionization energy decreases from top to bottom in groups, and increases from left to right across a period.
HGence, in this trend Francium (Fr) has the lowest ionization energy.