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प्रश्न
The number of electrons in the outermost shell of alkali metals is ______.
पर्याय
1
2
3
7
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उत्तर
The number of electrons in the outermost shell of alkali metals is 1.
Explanation:
Alkali metals belong to Group 1 of the periodic table, which includes elements like lithium, sodium, and potassium. They all have a valence electronic configuration of (ns1). Because they possess exactly one electron in their outermost shell, they easily lose it to form univalent positive ions (M+) and achieve a stable noble gas configuration.
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संबंधित प्रश्न
Write the electronic configuration of two elements X and Y whose atomic numbers are 20 and 17 respectively. Write the molecular formula of the compound formed when element X reacts with element Y. Draw the electron-dot structure of the product and also state the nature of the bond formed between both the elements.
Rewrite the following statement after correction, if necessary:
Isotopes are the elements of the same group.
Why do we classify elements?
The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):
-
1 18 a 2 13 14 15 16 17 b c d e
(i) Select the letter which represents an alkali metal.
(ii) Select the letter which represents a nobles gas.
(iii) Select the letter which represents a halogen.
(iv) What type of bond is formed between a and e?
(v) What type of bond is formed between d and e?
Write the names and symbols of two very reactive metals belonging to group 1 of the periodic table. Explain by drawing electronic structure, how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.
Rearrange the columns 2 and 3 so as to match with the column 1.
| Column 1 | Column 2 | Column 3 |
| i. Triad | a. Lightest and negatively charged particle in all the atoms | 1. Mendeleev |
| ii. Octave | b. Concentrated mass and positive charge | 2. Thomson |
| iii. Atomic number | c. Average of the first and the third atomic mass | 3. Newlands |
| iv. Period | d. Properties of the eighth element similar to the first | 4. Rutherford |
| v. Nucleus | e. Positive charge on the nucleus | 5. Dobereiner |
| vi. Electron | f. Sequential change in molecular formulae | 6. Moseley |
Answer the following question.
Write the name, symbol, and electronic configuration of an element X whose atomic number is 11.
How did the early chemists classify elements?
The basis of the classifications proposed by Dobereiner, Newlands and Mendeleev was ______.
Example for liquid metal is ______.
State whether true or false. If false, correct the statement.
Metals can gain electrons.
Which of the following have inert gases 2 electrons in the outermost shell.
Consider the following elements 20Ca, 8Or 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be in group 16 of the Periodic Table?
The element with atomic number 26 will be found in group ______
Which of the following metals have low melting and boiling point?
Relate the names of the following scientists with the statements given below.
Arranged elements into groups containing three elements each.
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.
Identify the following:
An element in Period 1 which can be placed in both Group 1 and Group 17 of the Periodic Table.
