Short Answer TypeAssign the position of the element having outer electronic configuration:
(i) ns2np4 for n = 3
(ii) (n-1)d2ns2 for n = 4, and
(iii) (n-2) f7 (n-1)d1ns2 for n = 6, in the periodic table.
Give the atomic number and electronic configuration of the following elements:
(i) The third alkali metal
(ii) The second transition element
(iii) The fourth noble gas
(iv) The first halogen.
Long Answer TypeElements A, B, C and D have atomic numbers 7, 19, 29 and 36 respectively. Write the electronic configuration and also predict their period, group and block.
The elements Z = 107 and Z = 109 have been made recently; element Z = 108 has not been made. Indicate the groups in which you will have the above elements.
Short Answer TypeAn element belongs to third period of the p-block. It has four valence electrons. Predict its group. How many unpaired electrons does it has?
The elements with Z = 117 and 120 have not yet been discovered. In which family/group would you place these elements. Also give the electronic configuration in each case.
Long Answer TypeWhat are metals, non-metals and metalloids?
Metals: Metals are generally solids at room temperature (mercury is an exception), lustrous, malleable, ductile, high melting and boiling points and good conductors of heat and electricity. Metals comprise more than 75% of all known elements and appear on the left side of the perodic table. For example iron, copper, aluminium, lead etc. The elements become more metallic as we go down a group.
Non-metals: Non-metals are usually solids or gases at room temperature, non-lustrous, low melting and boiling points and poor conductors of heat and electricity. They are located at the top right hand side of the periodic table. For example oxygen, hydrogen, carbon, sulphur, etc.
The non-metallic character increases as we go from left to right across the periodic table.
Metalloids or semimetals: These are the elements which show common characteristic of metals and non-metals. For example, germanium, silicon, arsenic, antimony and tellurium.
Short Answer TypeArrange the following elements in the increasing order of their metallic character: Si, Be, Mg, Na, P.
What are periodic properties of the elements? Name a few important periodic properties.
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