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प्रश्न
Choose the correct option and rewrite the statement.
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.
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संबंधित प्रश्न
State whether the following statement is true of false:
The elements in a group have consecutive atomic numbers.
Rewrite the following statement after correction, if necessary:
Periods are the horizontal rows of elements.
The element which forms a basis oxide has the atomic number of:
(a) 18
(b) 17
(c) 14
(d) 19
Find the neutral atom in the periodic table which has the same number of electrons as K+ and Cl−. What is this number?
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.
A non-metal X which is the largest constituent of air combines with hydrogen when heated in the presence of iron as catalyst to form a gas Y. When gas Y is treated with sulphuric acid, it forms a compound Z which is used as a chemical fertiliser.
(a) What are X, Y and Z?
(b) To which group of periodic table does X belong?
(c) Name the periodic table in which X is placed.
(d) Which element is placed just before X in the period?
(e) Which element is placed just after X in the period?
An element X (atomic number 17) reacts with an element Y (atomic number 20) to form a compound.
(a) Write the position of these elements in the modern periodic table.
(b) Write the formula of the compound formed.
Justify your answer in each case.
The molecular formula of the chloride of element X is XCl. This compound is a solid having a high melting point. Which of the following elements be present in the same group as X.
The number of periods and groups in the periodic table are ______
Identify the bond between H and F in the HF molecules.
Which one of the following statements is not correct about the trends in the properties of the elements of a period on going from left to right?
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?
Which one of the following statements is not correct about the trends in the properties of the elements of a group on going down in a group?
Which type of elements are poor conductors of heat and electricity?
An element is placed in 2nd Group and 3rd Period of the Periodic Table, burns in presence of oxygen to form a basic oxide.
- Identify the element
- Write the electronic configuration
- Write the balanced equation when it burns in the presence of air
- Write a balanced equation when this oxide is dissolved in water
- Draw the electron dot structure for the formation of this oxide
Relate the names of the following scientists with the statements given below.
Arranged elements into groups containing three elements each.
Complete the following triads by inserting the missing elements.
Li, ______, K
How are elements grouped into various families in the periodic table?
