Periodic Classification of Elements
Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-aluminium and eka-silicon.
(a) Name the element which has taken the place of (i) eka-aluminium and (ii) eka-silicon.
(b) Mention the period/ periods of these elements in the modern periodic table.
(c) Write the group/groups of these elements in the modern periodic table.
(d) Classify these elements as metals, non-metals or metalloids.
(e) How many valence electrons are present in the atoms of each of these elements?
Periodic Classification of Elements
An element barium has atomic number $$ 56 $$ . Look up its position in the periodic table and answer the following questions :
What is its valency ?
Periodic Classification of Elements
This question refers to the elements of the periodic table with atomic number from $$ 3 $$ to $$ 18 $$. Some of the elements are shown by letters , but 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 an element with valency $$ 4 $$ ?
Periodic Classification of Elements
The electronic configuration of an element T is $$ 2 , 8 , 8 , 1 $$ .
What is the valency of T ?
Periodic Classification of Elements
A metal M forms as oxide having the formula $$ M_2O_3 $$. It belongs to third period . Write the atomic number and valency of the metal.
Periodic Classification of Elements
The table given above represents the first three periods. Study the table and answer the question as given below :
How many electrons are present in the valency of the element with atomic number $$18 $$ ?
Periodic Classification of Elements
An element A has an atomic number $$7$$ and mass number $$14.$$
$$B$$ has electronic configuration $$2,8,8.$$
$$C$$ has $$13$$ electrons, $$14$$ neutrons.
$$D$$ has $$18$$ protons and $$22$$ neutrons.
$$E$$ has electronic configuration $$2,8,8,1.$$
State valency of each element
Periodic Classification of Elements
Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-aluminium and eka-silicon.
(a) Name the element which has taken the place of (i) eka-aluminium and (ii) eka-silicon.
(b) Mention the period/ periods of these elements in the modern periodic table.
(c) Write the group/groups of these elements in the modern periodic table.
(d) Classify these elements as metals, non-metals or metalloids.
(e) How many valence electrons are present in the atoms of each of these elements?
Periodic Classification of Elements
Which shows maximum valency?
Periodic Classification of Elements
In any short period the valency of an element with respect to oxygen
