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प्रश्न
Right or wrong sentence.
The size of an atom depends on the number of valence electrons.
पर्याय
Right
Wrong
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उत्तर
The given sentence is wrong.
Explanation:
Atomic size is determined mainly by the principal quantum number (which shell the valence electrons occupy) and by effective nuclear charge and shielding, not simply the count of valence electrons. Atoms down a group get a new shell, so size increases, while across a period, added electrons stay in the same shell, but higher nuclear charge pulls them closer, so size decreases.
संबंधित प्रश्न
Which is greater in size an atom or an anion?
Arrange the following in order of increasing radii:
CI- , CI
Write the name and symbol of the element from the description.
The atom having the smallest size.
Give scientific reasons for the following:
Atomic radius goes on decreasing while going from left to right in a period.
Study the radius of the element given below and answer the following questions.
| elements | K | Na | Rb | Cs | Li |
| Atomic radius (pm) | 231 | 186 | 244 | 262 | 151 |
a) Which of the above elements have the smallest atom?
b) In which group of the modern periodic table the above element are belongs?
c) What is the periodic trend observed in the variation of atomic radii down a group?
The metals of Group 2 from top to bottom are Be, Mg, Ca, Sr and Ba. Which one of these elements will form ions most readily and why?
While going from top to bottom in a group the atomic radius ______.
Right or wrong sentence.
Nanometer unit is used to measure atomic radius.
Carbon belongs to the second period and Group 14. Silicon belongs to the third period and Group 14. If the atomic number of carbon is 6, the atomic number of silicon is ______
An element X has mass number 40 and contains 21 neutrons in its atom. To which group of the Periodic Table does it belong?
Which of the following is the correct order of size?
Which of the following gives the correct increasing order of the atomic radii of O, F, and N?
When an atom of iodine becomes an iodine ion (I–) the radius will ______
Which of the following are the characteristics of isotopes of an element?
- Isotopes of an element have same atomic masses
- Isotopes of an element have same atomic number
- Isotopes of an element show same physical properties
- Isotopes of an element show same chemical properties
Atomic number of a few elements are given below
10, 20, 7, 14
- Identify the elements
- Identify the Group number of these elements in the Periodic Table
- Identify the Periods of these elements in the Periodic Table
- What would be the electronic configuration for each of these elements?
- Determine the valency of these elements
Arrange the following as per the instruction given in the bracket:
Carbon, Fluorine, Beryllium (decreasing order of atomic size).
Arrange the following in order of increasing radii:
Mg2+, Mg, Mg+
Explain your choice.
Arrange the following in order of increasing radii:
N, O, P
Explain your choice.
