Periodic Classification of Elements
The electronic configuration of an element is $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}$$. The atomic number of the element which is just below the above element in the periodic table is :
Give the formula and valency of aluminium.
Name Formula Valency
aluminium $$Al$$ $$+3$$
The electronic configuration of an element is $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}$$. The atomic number of the element which is just below the above element in the periodic table is :
An element $$X$$ belongs to group III-A and 4th period in the periodic table. Find out the atomic numbers of $$X$$ and the element which is placed just below $$X$$ in the periodic table.
(a) What are the following groups known as? (i) Group $$18$$ (ii) Name two elements of the group.
The element $$X$$ in group $$17$$ has $$3$$ shells. If so, Write the subshell electronic configuration of the element.
Identify the incorrect match. Name IUPAC Official Name a) Unnilunium i) Mendelevium b) Unniltrium ii) Lawrencium c) Unnilhexium iii) Seaborgium d) Unununnium iv) Darmstadtium
(a) What are the following groups known as? (i) Group $$18$$ (ii) Name two elements of the group.
This question refers to elements of the periodic table with atomic numbers from $$3$$ to $$18$$. In the table below, some elements are shown by letters, even though the letters are not the usual symbols of the elements. $$3$$ $$4$$ $$5$$ $$6$$ $$7$$ $$8$$ $$9$$ $$10$$ $$A$$ $$B$$ $$C$$ $$D$$ $$E$$ $$F$$ $$G$$ $$H$$ $$11$$ $$12$$ $$13$$ $$14$$ $$15$$ $$16$$ $$17$$ $$18$$ $$I$$ $$J$$ $$K$$ $$L$$ $$M$$ $$N$$ $$O$$ $$P$$ Which of these is a halogen?
An element $$X$$ belongs to group III-A and 4th period in the periodic table. Find out the atomic numbers of $$X$$ and the element which is placed just below $$X$$ in the periodic table.
If the valence shell electronic configuration for an element is $$ns^2np^5$$, this element belongs to the group of:
Litharge is chemically: