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प्रश्न
Write an explanation.
Electropositivity
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उत्तर
Electropositivity is the tendency of an atom to lose one or more electrons and form a positive ion (cation). Elements that easily donate electrons are called electropositive elements. Electropositivity increases down a group due to an increase in atomic size and decreases across a period due to an increasing nuclear charge.
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संबंधित प्रश्न
Choose the word or phrase from the brackets which correctly complete the following statement:
Metals are good ______ (oxidizing agents/reducing agents) because they are electron ______ (acceptors/donors).
Arrange the following as per the instructions given in the brackets:
Na, K, Cl, S, Si (increasing order ionization energy)
Complete the following sentences
Moving across a ………….. of the periodic table the elements show increasing ………………..character (group, period, metallic, non-metallic).
iii) Observe the figure and answer the following questions.
a) Identify the block shown by box A and write an electronic configuration of any one element of this block.
b) Identify the block of element denoted by letter B and write its period number.
In Period 3, the most metallic element is ______.
In the third period, which is the most metallic and most non-metallic element?
Within a group, where would you expect to find the element with the greatest metallic character.
Use the information given in (a) to (h) to identify the substances P to W selecting your answers from the given list.
| List | ||
| Calcium | Oxygen | Copper (II) Oxide |
| Carbon | Calcium hydroxide | Copper (II) Nitrate |
| Lead (II) Oxide | Hydrogen chloride | Chlorine |
| Lead (II) Nitrate | Calcium Oxide | Ammonium chloride |
- P is white solid. When heated produces white fumes (sublime).
- P and R on warming produce an alkaline gas.
- On adding water to T, heat is evolved and R is formed.
- Q burns brightly in the air to form T.
- When S is heated, it gives off brown fumes and leaves a black residue of U.
- A solution of S is formed by warming U with dilute nitric acid.
- V is a gaseous non-metallic element that reacts with hydrogen to form W.
- A solution of W will neutralize the solution of R.
The tendency of an element to form cation is the ______ character of that element.
Electropositivity means ______.
On moving down the group metallic character increases.
Electronegativity is the metallic property of an element.
An element has atomic number 17. To which group, the period does it belong? It is metal or non-metal?
Which of the following set of elements is written in order of their increasing metallic character?
Identify the elements with the following property and arrange them in increasing order of their reactivity
- An element which is a soft and reactive metal
- The metal which is an important constituent of limestone
- The metal which exists in liquid state at room temperature
Choose the odd one out and write the reason:
Arrange the following as per instruction given in the bracket.
Cs, Na, Li, K, Rb (increasing metallic character)
Metals are good ______ because they are electron ______.
The given table shows elements with the same number of electrons in its valence shell.
| Elements | A | B | C |
| m.p. | 63.0 | 180.0 | 97.0 |
Arrange them in order of increasing metallic character.
