Advertisements
Advertisements
प्रश्न
As element X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong?
उत्तर
X belongs to Group 1. The mass number of element X is 40 and the number of neutrons in its atom is 21. In order to find out the group to which the element belongs, we need to know the atomic number of the element. Once we know the atomic number of the element, the electronic configuration and valency can be determined.
Atomic number = Mass number - Number of Neutrons.
Atomic number = 40-21 =19
The electronic configuration of X is 2,8,8,1. The number of valence electrons in X is 1. Therefore, the valency of element X is 1. We know that group 1 elements have a valency of 1.
APPEARS IN
संबंधित प्रश्न
An element X is in group 2 of the periodic table what will be the formula of its oxide?
The element X forms a compound X2Y. Suggest an element that Y might be and give reasons for your choice.
An element A has an atomic number of 6. Another element B has 17 electrons in its one neutral atom.
(a) In which groups of the periodic table would you expect to find these elements?
(b) what type of bond is formed between A and B?
(c) Suggest a formula of the compound formed between A and B.
A non-metal X which is the largest constituent of air combines with hydrogen when heated in the presence of iron as catalyst to form a gas Y. When gas Y is treated with sulphuric acid, it forms a compound Z which is used as a chemical fertiliser.
(a) What are X, Y and Z?
(b) To which group of periodic table does X belong?
(c) Name the periodic table in which X is placed.
(d) Which element is placed just before X in the period?
(e) Which element is placed just after X in the period?
Why was this basis of classification discarded for future classification of elements?
Element ‘A’ has electronic configuration 2, 7; ‘B’ has electronic configuration 2, 8, 5 and ‘C’ has electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?
The element with atomic number 26 will be found in group ______
Which type of elements are poor conductors of heat and electricity?
How are elements grouped into various families in the periodic table?
The atomic number of an element 'X' is 11.
- Write the electronic configuration of X and find its valency.
- Write the formula and nature of its oxide.
