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प्रश्न
Consider the following elements:
Ca, Cl, Na, I, Li, Ba, Sr, K, Br
Separate these elements into three groups (families) of similar properties. State one property in each case on the basis of which you have made your choice.
उत्तर
(i) Lithium (Li), sodium (Na) and potassium (K) are three metals of group 1 having a valency of 1.
(ii) Calcium (Ca), strontium (Sr) and barium (Ba) are three metals of group 2 having a valency of 2.
(iii) Chlorine (Cl), bromine(Br) and iodine (I) are three non-metals of group 17 which are known as halogens, and have seven valence electrons.
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संबंधित प्रश्न
What are the groups in a periodic table? Give two characteristics of each.
State the term
The tabular arrangement of elements in horizontal rows and vertical columns _________
Answer the following question.
Define the atomic size. Give its unit of measurement. In the modern periodic table what trend is observed in the atomic radius in a group and a period and why is it so?
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Zinc
Give the symbol and valency of the following element and radical.
Sulphur [Sulphide]
State what is meant by the term chemical formula.
Which of the following statements about the Modern Periodic Table is correct:
An element X which is a yellow solid at room temperature shows catenation and allotropy. X forms two oxides which are also formed during the thermal decomposition of ferrous sulphate crystals and are the major air pollutants.
- Identify the element X
- Write the electronic configuration of X
- Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals?
- What would be the nature (acidic/ basic) of oxides formed?
- Locate the position of the element in the Modern Periodic Table.
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:
A and F
