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प्रश्न
Moving left to right in the second period, the number of valence electrons _____.
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उत्तर
Moving left to right in the second period, the number of valence electrons increases from 1 to 8.
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संबंधित प्रश्न
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
How do the atomic size and metallic character of elements vary as we move :-
(a) down a group and
(b) from left to right in a period
How does the electropositive character of elements change on going down in a group of the periodic table?
How do atomic structures (electron arrangements) change in a period with increase in atomic numbers from left to right?
What happens to the metallic character of the elements as we move from left to right in a period of the periodic table?
First ionization enthalpy of two elements X and Y are 500 KJ mol-1 and 375 KJ mol-1 respectively. Comment about their relative position in a group as well as in a period.
Atomic number of metal ‚A‛ is 11, while atomic number of metal ‚B‛ is 20. Which of them will be more reactive? Write the chemical reaction of dilute HCl with metal ‚A‛.
Arrange the following as per instruction given in the bracket
Na, K, Cl, S, Si (increasing ionisation potential)
Arrange the following as per instruction given in the bracket.
Cs, Na, Li, K, Rb (decreasing electronegativity)
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
