A 25 Watt Bulb Emits Monochromatic Yellow Light Of Wavelength Of 0.57 μm. Calculate The Rate Of Emission Of Quanta Per Second.

Calculate the uncertainty in the velocity of a wagon of mass 3000 kg whose position is known to an accuracy of ±10 pm

(Planck’s constant = 6.63 × 10^–34 Js) 

Calculate the uncertainty in the position of an electron if the uncertainty in its velocity is 5.7 × 10⁵ m/sec (h = 6.6 × 10^–34 kg m² s^–1, mass of the electron = 9.1×10^–31 kg).

A golf ball has a mass of 40 g and a speed of 45 m/s. If the speed can be measured within accuracy of 2%, calculate the uncertainty in position.

If an electron is moving with a velocity 600 ms^–1 which is accurate upto 0.005%, then calculate the uncertainty in its position. 

  (h = 6.63 × 10^–34 Js, mass of electron = 9.1 × 10^–31 kg) 

What is the transition in the hydrogen spectrum would have the same wavelength as the Balmer transition, n = 4 to n = 2 of He⁺ spectrum?

Calculate the energy required for the process

           He⁺ (g) → He²⁺ (g) + e^–   

The ionization energy for the H atom in the ground state is

 2.18 × 10^–18 J atom^–1.  

What is the wavelength of the light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n = 2? What is the colour corresponding to this wavelength? (Rydberg constant = 109,677 cm^–1)   

A certain particle carries 2.5 × 10^–16 C of static electric charge. Calculate the number of electrons present in it.

An ion with mass number 37 possesses one unit of negative charge. If the ion contains 11.1% more neutrons then the electrons, find the symbol of the ion.    

An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.