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प्रश्न
What are orbits or shells ?
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उत्तर
The fixed circular paths along which electrons revolve round the nucleus.
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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?
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 |
TRUE \ FALSE
Cathode rays are a stream of fast moving particles that travel in random directions.
WRITE SHORT ANSWER
Name three inert gases.
ANSWER IN DETAIL
State the postulates of the Dalton’s atomic theory.
Write the names of `"FeS"` compounds :
Fill in the blank:
Atoms are _____
Write electronic configuration of oxygen, fluorine, sodium, silicon, argon.
What does the word ‘atom’ mean?
An atom has 13 protons and 14 neutrons.
What is the atomic number of the atom ?
An atom has 13 protons and 14 neutrons.
How many electrons would be present in this atom ?
Define: An Atom:
Fill in the blank
A deficiency of electrons produces a ________ charge.
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.
For the symbols H, D and T, write the subatomic particles (protons, neutrons and electrons) found in each one of them.
A compound containing one atom of carbon and two atoms of oxygen is ______.
A change in the physical state can be brought about
Does the solubility of a substance change with temperature? Explain with the help of an example.
The graphite refill used is pencil is made of element called ______.
The first scientific theory about atoms was given by J J. Thomson.
