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प्रश्न
State the main postulates of Dalton’s atomic theory.
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उत्तर
- Matter consists of small indivisible particles called atoms, i.e., an atom is the basic unit of matter.
- Atoms of the same element are alike in all respects, i.e., atoms of hydrogen have the same properties, such as mass and density, and atoms of oxygen are alike in all respects.
- Atoms of different elements are different from each other. i.e., atoms of hydrogen are different from atoms of oxygen.
- An atom can neither be created nor destroyed.
- Atoms combine with other atoms in a simple whole-number ratio, forming compounds or molecules.
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संबंधित प्रश्न
Dalton said that ______ could not be divided.
Write true or false for the following statement
An atom on the whole has a positive charge.
Tick the most appropriate answer.
Which of these have similar chemical properties but different set of physical properties and mass number?
- isobars
- elements
- isotopes
- none of these
From the symbol `""_12^24"Mg"`
, state the mass number, the atomic number and electronic configuration of magnesium.
Match the atomic numbers 4,8,10,15 and 19 with the following:
Element with four shells
Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
Phosphorus – \[\ce{^31_15P}\]
[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]
The diagram represents an isotope of hydrogen [H]. Answer the following:
Atomic no. = 1
Mass no. = 1
If an isotope of ‘H’ has mass no. = 3, how many neutrons does it have.
Define the term of atomic number.
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
Mass No =______ + No. of Neutrons.
