a. What is the atomic number of this element?
Answer. The atomic number of this element is 2 + 8 + 2 = 12.
b. What is the group of this element.
Answer. The electronic configuration of the given element is 2, 8. 2 which shows that this element has 2 valence electrons. Hence the given element is placed in group 2.
c. To which period does this element belong?
Answer. The electronic configuration of the given element is 2, 8, 2 which shows that the electrons are arranged in 3 shells. Hence the given element is placed in third period.
d. With which of the following elements would this element resemble?
(Atomic numbers are given in the brackets) N (7), Be (4) , Ar (18), Cl (17).
Answer. Electronic Configuration:
N (7) – 2 , 5 Be (4) – 2, 2 Ar (18) – 2 , 8, 8 Cl (17) – 2, 8, 7
The element Beryllium (Be) has valence electron 2 just like the given element. Hence this element will be chemically similar to the given element which has the same number of valence electrons in its atoms.
