|
The given figure depicts the atomic structure of an atom of an element ‘X’. Write the following information about the element ‘X’
|
|
0
|
11382
|
March 20, 2018
|
|
Show diagrammatically the electron distribution in a sodium atom and a sodium ion and also give their atomic number
|
|
0
|
4150
|
March 20, 2018
|
|
The ratio of the radii of hydrogen atom and its nucleus is ~10^5
|
|
0
|
2415
|
March 20, 2018
|
|
What are the postulates of Bohr’s model of an atom?
|
|
0
|
7104
|
March 20, 2018
|
|
In what way is the Rutherford’s atomic model different from that of Thomson’s atomic mode
|
|
0
|
1311
|
March 20, 2018
|
|
What is the gold foil experiment?
|
|
0
|
5899
|
March 20, 2018
|
|
State the method of determining the valency of an element if its atomic number is given
|
|
0
|
2907
|
March 20, 2018
|
|
Write the formula of the compounds formed by the following ions. Mg2+ and S2- Cu2+ and OH-
|
|
0
|
17140
|
March 20, 2018
|
|
Write the molecular formulae of all the compounds that can be formed by the combination of following ions
|
|
0
|
619
|
March 20, 2018
|
|
Write the molecular formulae for the following compounds:
|
|
0
|
600
|
March 20, 2018
|
|
. What information do you get from the figures about the atomic number, valency of atoms X, Y and Z? Give your answer in a tabular form
|
|
0
|
831
|
March 20, 2018
|
|
How many protons, neutrons and electrons are there in one atom of this radon isotope?
|
|
0
|
2053
|
March 20, 2018
|
|
In the atom of an element ‘Z’, 5 electrons are present in the outermost shell
|
|
0
|
6728
|
March 20, 2018
|
|
Complete the table on the basis of information available in the symbols given below
|
|
0
|
1164
|
March 20, 2018
|
|
The atomic number of lithium is 3. Its mass number is 7
|
|
0
|
4293
|
March 20, 2018
|
|
An element ‘X’ contains 6 electrons in ‘M’ shell as valence electrons:
|
|
0
|
7668
|
March 20, 2018
|
|
Predict the valency of the following elements
|
|
0
|
4786
|
March 20, 2018
|
|
In the gold foil experiment of Geiger and Marsden, that paved the way for Rutherford’s model of an atom, ~ 1.00% of the alpha-particles were found to deflect at angles > 50°
|
|
0
|
2055
|
March 20, 2018
|
|
List any three distinguishing features between the models of an atom proposed by J.J. Thomson and Ernest Rutherford
|
|
0
|
3612
|
March 20, 2018
|
|
An element ‘Z’ forms the following compound when it reacts with hydrogen, chlorine, oxygen and phosphorous
|
|
0
|
6263
|
March 20, 2018
|
|
An element ‘X’ has a valency 3(+):
|
|
0
|
4164
|
March 20, 2018
|
|
Why do isotopes show similar chemical properties
|
|
0
|
545
|
March 20, 2018
|
|
Calculate the number of neutrons present in the nucleus of an element X
|
|
0
|
989
|
March 20, 2018
|
|
Identify the Na+ ion from the following figures. What is the valency of sodium atom? Give reason
|
|
0
|
6342
|
March 20, 2018
|
|
Find out the valency of the atoms represented by the Figs, (a) and (b)
|
|
0
|
830
|
March 20, 2018
|
|
Helium atom has 2 electrons in its valence shell but its valency is not 2. Explain
|
|
0
|
1621
|
March 20, 2018
|
|
Why do helium, neon and argon have a zero valency?
|
|
0
|
8795
|
March 20, 2018
|
|
Define valence electrons. Which electrons of an atom are involved in the chemical bond formation with other atoms?
|
|
0
|
2789
|
March 20, 2018
|
|
Write down the electron distribution of chlorine atom
|
|
0
|
2133
|
March 20, 2018
|
|
The atomic number of Al and Cl are 13 and 17, respectively. What will be the number of electrons in Al3+ and Cl-?
|
|
0
|
1864
|
March 20, 2018
|