Choose metalloid from the following
Boron
Sodium
Chlorine
Aluminium
The long form of periodic table is based on Bohr’s atomic model. It consists of eighteen groups and seven periods. The periods are numbered 1, 2, 3, 4, 5, 6, and 7 and each number respectively refers to the addition of last electron to the 1st, 2nd, 3rd, 4th…etc., energy levels.Which atomic number represents an element of period 4 of the periodic table?
10
14
17
20
The energy released when an electron is gained by a neutral gaseous atom to become negatively charged ion is
Ionisation energy
electron affinity
chemical energy
physical energy
Which of the following electronic configurations represents the element whose chemical properties are similar to those of phosphorus?
(2,2)
(2,5)
(2,8,1)
(2,8,6)
In the modern periodic table, elements are arranged in the order of their
increasing atomic masses
increasing atomic numbers
decreasing atomic masses
decreasing atomic numbers
Which of following species does not have electrons equal to 18?
S2-
Cl -
Ca2+
K0
Elements have the same number of valence electrons are placed in same
group
table
period
not possible
Which one of the following oxides is an amphoteric oxide
Cl2O7
Al2O3
CaO
Na2O
