CBSE - Class 11 Chemistry Structure of Atom Worksheet
1.
What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is $-2.18 \times 10^{-11}$ ergs.
2.
Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency ($\nu_0$) and work function ($W_0$) of the metal.
3.
The diameter of zinc atom is 2.6 Å. Calculate (a) radius of zinc atom in pm and (b) number of atoms present in a length of 1.6 cm if the zinc atoms are arranged side by side lengthwise.
4.
The bromine atom possesses 35 electrons. It contains 6 electrons in 2p orbital, 6 electrons in 3p orbital and 5 electron in 4p orbital. Which of these electron experiences the lowest effective nuclear charge ?
5.
Write the complete symbol for the atom with the given atomic number ($Z$) and atomic mass ($A$) (ii) $Z$ = 92, $A$ = 233.
6.
(i) Write the electronic configurations of the following ions: (c) O$^{2-}$
7.
Give the number of electrons in the species H$_2^+$, H$_2$ and O$_2^+$
8.
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.
9.
(i) The energy associated with the first orbit in the hydrogen atom is $-2.18 \times 10^{-18}$ J atom$^{-1}$. What is the energy associated with the fifth orbit?
10.
Calculate the wavelength for the emission transition if it starts from the orbit having radius 1.3225 nm and ends at 211.6 pm. Name the series to which this transition belongs and the region of the spectrum.
11.
Calculate the wavelength of an electron moving with a velocity of $2.05 \times 10^7$ m s$^{-1}$.
12.
(ii) Calculate the mass and charge of one mole of electrons.
13.
What is the number of photons of light with a wavelength of 4000 pm that provide 1J of energy?
14.
Calculate the energy required for the process He$^+$ (g) $\rightarrow$ He$^{2+}$ (g) + e$^-$ The ionization energy for the H atom in the ground state is $2.18 \times 10^{-18}$ J atom$^{-1}$
15.
Indicate the number of unpaired electrons in : (a) P,
16.
What is the maximum number of emission lines when the excited electron of a H atom in $n$ = 6 drops to the ground state?
17.
(iii) Which atoms are indicated by the following configurations ? (a) [He] $2s^1$
18.
Following results are observed when sodium metal is irradiated with different wavelengths. Calculate (a) threshold wavelength and, (b) Planck’s constant. $\lambda$ (nm) 500 450 400, $v \times 10^{-5}$ (cm s$^{-1}$) 2.55 4.35 5.35
19.
The electron energy in hydrogen atom is given by $E_n = (–2.18 \times 10^{-18})/n^2$ J. Calculate the energy required to remove an electron completely from the $n$ = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?
20.
(iii) Which atoms are indicated by the following configurations ? (b) [Ne] $3s^2 3p^3$
