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प्रश्न
What is an atom ? How do atoms usually exist ?
उत्तर
Atoms are building blocks of all matter. They are the smallest particles of elements that can take part in a chemical reaction.
Atoms usually exist in combined form, in two ways:
- in the form of molecules
- in the form of ions
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संबंधित प्रश्न
The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes `""_8^16X" and """_8^18X` in the sample?
WRITE SHORT ANSWER
Define an ionic compound.
ANSWER IN DETAIL
Enlist the features of Bohr’s model of an atom. How did he correct the Rutherford’s model ?
Fill in the blank:
Atoms are _____
Give the charge and the mass of an electron, proton and neutron present in an atom ?
Name the particle or particles you would expect to find in :
The orbit of an atom
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is such a particle called ?
Name the three subatomic particles present in an atom.
How many times is a proton heavier than an electron?
An atom of an element X may be written as `""_9^4"X"`
(a) What does the figure 9 indicate?
(b) What does the figure 4 indicate?
(c) What is the number of protons in atom X?
(d) What is the number of neutrons in atom X?
(e) What is the number of electrons in atom X?
(f) How many electrons are there in the outermost shell of an atom of element X?
(g) Write the symbol of ion formed by an atom of element X.
Give brief information of three subatomic particles with reference to electrical charge, mass and location.
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
Which will form negative ion?
Select the correct answer to the statement given below:
The basic unit of matter is not capable of independent existence.
State true or false. If false, correct the statement.
The basic unit of an element is molecule.
Define – Atom.
The smallest unit of an element is ______.
______ is a substance that is made up of three oxygen atoms chemically combined.
What is the fundamental particle of an element?
