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प्रश्न
State true or false. If false, correct the statement.
The basic unit of an element is molecule.
विकल्प
True
False
उत्तर
False
Correct statement: The basic unit of an element is atom.
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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 the names of the elements present in the :-
Sulphuric acid
Write the names of the elements present in the:-
Glucose
Write the names of the elements present in the:-
Acetic acid
Fill in the blank:
Atoms are _____
Define: Mass number
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is the mass number of X ?
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is the atomic numebr of X ?
Fill in the blank
An excess of electrons produces a ________ charge.
Dalton's atomic theory says that atoms are indivisible. Is this statement still valid ? Give reasons for your answer.
State two observations which show that atom is not indivisible.
One nm is equal to :
Give scientific reason.
All the mass of an atom is concentrated in the nucleus.
Match the pairs.
| Group 'A' | Group 'B' |
| a. Proton | i. Negatively charged |
| b. Electron | ii. Neutral |
| c. Neutron | iii. Positively charged |
Deduce from the datum provided.
| Datum | To deduce |
| \[\ce{_11^23Na}\] | Neutron number |
| \[\ce{_6^14C}\] | Mass number |
| \[\ce{_17^37 Cl}\] | Proton number |
Name the gas that.
Turns moist starch iodide paper blue black.
Draw the diagrams representing the atomic structures of the following: Neon
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
What will be the charge present of the molecule XY after chemical combination?
Rewrite the given sentence in correct form.
Elements contain two or more kind of atoms and compounds contain only one kind of atom.
______ is the smallest particle of an element.
The volume occupied by 1 mole of a diatomic gas at S.T.P is ______
Atoms of one element can be transmuted into atoms of other elements by ______
Dalton’s atomic theory successfully explained
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportions
The graphite refill used is pencil is made of element called ______.
What is the fundamental particle of an element?
The ______ are combination of atoms of various elements or the same element.
The first scientific theory about atoms was given by J J. Thomson.
