Class 11th

Three elements X, Y and Z are in the 3rd period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is:

Two elements A and B have similar chemical properties. They don't form solid hydrogencarbonates, but react with nitrogen to form nitrides. A and B, respectively, are:

Match the type of interaction in column A with the distance dependence of their interaction energy in column B:

The internal energy change (in J) when 90 g of water undergoes complete evaporation at 100°C is 
(Given: ΔH_vap for water at 373K = 41 kJ/mol, R = 8.314 JK?¹mol?¹)

The number of subshells associated with n=4 and m=-2 quantum numbers is:

The figure that is not a direct manifestation of the quantum nature of atom is

The figure that is not a direct manifestation of the quantum nature of atom is:

Shown in the figure is rigid and uniform one meter long rod AB held in horizontal position by two strings tied to its ends and attached to the ceiling. The rod is of mass 'm' and has another weight of mass 2m hung at a distance of 75 cm from A. The tension in the string at A is:

Train A and train B are running on parallel tracks in opposite directions with speed of 36 km/hour and 72 km/hour, respectively. A person is walking in train A in the direction opposite to its motion with a speed of 1.8 km/hour. Speed (in ms⁻¹) of this person as observed from train B will be close to: (take the distance between the tracks as negligible)

A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. Assuming the gases to be ideal and the oxygen bond to be rigid, the total internal energy (in units of RT) of the mixture is: