Advertisements
Advertisements
Question
What is the number of elements in the 1st period?
Advertisements
Solution
There are two elements in the first period.
APPEARS IN
RELATED QUESTIONS
Fill in the following blank with suitable word:
Group 17 elements are known as ...............
Explain why, the noble gases are placed in a separate group.
Which element has two shells, both of which are completely filled with electrons?
Give alongside is a part of the periodic table :
As we move horizontally from left to right:
| Li | Be | B | C | N | O | F | |
| Na | Mg | Al | Si | P | S | Cl |
(i) What happens to the metallic character of the elements?
(ii) What happens to the atomic size?
Consider the following elements:
20Ca, 8O, 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be:
(i) very stable?
(ii) in group 2 of the periodic table?
(iii) in group 16 of the periodic table?
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
Compare Modern Periodic Law with Mendeleev's Periodic Law.
If an element X is placed in group 14, what will be the formula and the nature of bonding of its chloride?
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has same valency as Lithium.
A part of modern periodic table is given below. On its basis, answer the following questions:
| Group No. → | 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 |
| Period ↓ | ||||||||
| 2 | A | B | ||||||
| 3 | E | D | F | C |
Write the molecular formula of the compound formed by the combination:
E and B
