10. Which of the following statement describe theory of Demographic Transition
a) Human ingenuity can resolve any environment or social issues and therefore there will
always be an increase in population,
b) The health of human population depends on the environment and not just food supply
c) Rate of population growth is higher than growth of agricultural products
d) All societies follow a typical pattern of population growth related to development.
Answers
Answer:
↦ The electronic configuration of an element T is 2 , 8 , 8 , 1.
To Find :-
What is the group number of T.
What is the period number of T.
How many valence electrons are there in an atom of T.
What is the valence of T.
Is it a metal or non-metal.
Solution :-
\bigstar★ (i) What is the group number of T :
\implies⟹ The number of electrons in the outer most shells is n = 4 is 1.
So, it is belong to the group no 1.
\rule{150}{2}
\bigstar★ (ii) What is the period number of T :
\implies⟹ The number of electrons in the outer most shells is 4.
So, it has a period number of T is 4.
\rule{150}{2}
\bigstar★ (iii) How many valence electrons are there in an atom of T :
\implies⟹ It has only one electrons in the outer most shells.
So, there are only one valence electron.
\rule{150}{2}
\bigstar★ (iv) What is the valency of T :
\implies⟹ As it is T need to lose one electron to complete it's octet.
So, the valency of T is 1.
\rule{150}{2}
\bigstar★ (v) Is it a metal or non-metal :
\implies⟹ As it is has only one electrons in the outer most shells.
So, it is a metal.
\rule{150}{2}
EXTRA INFORMATION :
➲ Groups and their names :
1) Group-1 elements ➠ Alkali Metals
2) Group-2 elements ➠ Alkali earth metals
3) Group-11 elements ➠ Coinage metals
4) Group-15 elements ➠ Pnictogens
5) Group-16 elements ➠ Chalcogens
6) Group-17 elements ➠ Halogens
7) Group-18 elements ➠ Noble Gases
Answer:
Rain water harvesting is a technique of collection and storage of rain water in surface (storage tanks) or sub surface aquifer before it is lost as surface runoff.