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प्रश्न
Why is it not possible to see an atom with naked eyes?
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उत्तर
The size of an atom is so small that it is not possible to see it with the naked eye. Also, an element's atom does not exist independently (its atomic radius is of the order of 10-10 m).
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संबंधित प्रश्न
MATCH THE COLUMNAS
| 1. Jpham Dalton | a. Neutrons |
| 2. Atom | b. Model of the atom |
| 3. Chadwick | c.The atomic theory of matter |
| 4. Rutherfrod | d. Positively charged |
| 5. Protons | e. Electricity neutral |
| 6. Nuclear fusion | f. Generator of electricity |
| 7.Gamma -rays | g. High penetrating power |
| h.Energy in sun |
Define:- Atom
Write the names of the elements present in the :-
Sulphuric acid
Write the names of the elements present in the:-
Sodium hydroxide
Define: Ions
Give two examples for each of ionic and covalent bond.
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is the mass number of X?
Fill in the blank
An _______ is electrically neutral.
Write the relation between nanometre and metre.
The electronic configuration of an element Z is 2, 8, 8.
(a) What is the atomic number of the element?
(b) State whether element Z is a metal or a non-metal.
(c) What type of ion (if any) will be formed by an atom of element Z? Why?
(d) What is special about the outermost electron shell of the atom of this element?
(e) Give the name and symbol of element Z.
(f) Name the group of elements to which Z belongs.
Which of the following statement is correct about the atom of an element ?
Which has more atoms, 50 g of aluminium or 50 g of iron ? Illustrate your answer with the help of calculations.
(Atomic masses : Al = 27 u ; Fe = 25 u)
Give scientific reason.
All the mass of an atom is concentrated in the nucleus.
A radical take part – unsplit in a chemical reaction and retains its identity in reactions.
With reference to the radical –
- ammonium
- bisulphate
- carbonate
state the group of atoms present in each radical.
Select the correct answer to the statement given below:
The basic unit of matter is not capable of independent existence.
Define – Atom.
In the nucleus of `""_20"Ca"^40`, there are ______
Atoms of different elements having the same number of ______ are called isotones.
The graphite refill used is pencil is made of element called ______.
Lead is also known as plumbum.
