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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
If number of electrons in an atom is 8 and number of protons is also 8, then
- What is the atomic number of the atom? and
- What is the charge on the atom?
What are the atomic numbers of elements whose outermost electrons is represented by 2p3.
Multiple Choice Questions
The sub atomic particle with negative charge is
TRUE \ FALSE
After the emission of a beta-particle, the atomic number of the atom increases by one.
The number of electrons in the atom of an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of an atom of this element ?
Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
Argon – \[\ce{^40_18Ar}\]
[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]
‘Valency is the number of hydrogen atoms which can combine with [or displace] one atom of the element [or radical] forming a compound’. With reference to the above definition of valency, state the valency of chlorine in hydrogen chloride, giving reasons.
The diagram represents an isotope of hydrogen [H]. Answer the following:
Atomic no. = 1
Mass no. = 1
Do isotopes have the same atomic number or the same mass number?
Every atom has an equal number of protons and electrons. The nature of the atom is ______.
If an atom has 6 electrons in its outermost shell, it is inert.
