Advertisements
Advertisements
प्रश्न
An element A has 2 electrons in its fourth shell. State:
is it a metal or non-metal
Advertisements
उत्तर
It's a metal.
APPEARS IN
संबंधित प्रश्न
Given below are some elements of the modern periodic table. Atomic number of the element is given in parentheses.
A(4), B(9), C(14), D(19), E(20)
(a) Select the element that has one electron in the outermost shell. Also, write the electronic configuration of this element.
(b) Which two elements amongst these belong to the same group? Give reasons for your answer.
(c) Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?
Na, Mg and Al are the elements of the same period of Modern Periodic Table having, one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason for each case.
Which element has the electronic configuration 2, 8, 2?
Which element has a total of three shells, with four electrons in its valence shell?
Name the element which is in seventeenth group and second period.
How does the tendency to gain electrons change as we go down in group 17 of the periodic table? Why does it change this way?
The atomic numbers of three elements A, B and C are given below:
| Element | Atomic number |
| A | 5 |
| B | 7 |
| C | 10 |
(i) Which element belongs to group 18?
(ii) Which element belongs to group 15?
(iii) Which element belongs to group 13?
(iv) To which period/periods do these elements belong?
An element 'X' (Atomic number – 20) burns in the presence of oxygen to form a basic oxide.
(a) Identify the element and write its electronic configuration.
(b) State its group number and period number in the Modern Periodic Table.
(c) Write a balanced chemical equation for the reaction when this oxide is dissolved in water.
What will be the valency of an element of atomic number 9 (nine)?
Arrange the following as per instruction given in the bracket.
K, Pb, Ca, Zn (increasing reactivity)
