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प्रश्न
Give scientific reason.
All the mass of an atom is concentrated in the nucleus.
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उत्तर
All the mass of an atom is concentrated in the nucleus because the atom contains three subatomic particles like electron, proton and neutron. Out of which, the nucleus present at the centre of an atom contains two subatomic particles that are protons and neutrons, and the mass of the nucleus is the sum of the mass of protons and neutrons located at the centre of an atom.
संबंधित प्रश्न
Why is it not possible to see an atom with naked eyes?
ANSWER IN DETAIL
State the postulates of the Dalton’s atomic theory.
Define:- Atom
Define:- Radicals
Write the names of the elements present in the:-
Ammonia
Write the names of `"Ca"("NO"_3)_2` compounds :
Write the names of `"Na"_3"PO"_4` compounds :
What are orbits or shells ?
Give two examples for each of ionic and covalent bond.
How did Neils Bohr visualise the atom ?
State two observations which show that atom is not indivisible.
An atom of element E contains 3 protons, 3 electrons and 4 neutrons :
(a) What is its atomic number?
(b) What is its mass number?
(c) Write the electronic configuration of the element E.
(d) State whether element E is a metal or non-metal. Why?
(e) What type of ion, cation or anion, will be formed by an atom of element E? Why
(f) Write the symbol of the ion formed by an atom of element E.
(g) What could element X be?
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.
Define the following term:
Atom
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
Which element will lose electron?
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.
Assertion: An atom is electrically neutral.
Reason: Atoms have equal number of protons and electrons.
Define the following term with an example.
Compound
Define the following term with an example.
Non-metal
A sample of vitamic C is known to contain 2.58 ×1024 oxygen atoms. How many moles of oxygen atoms are present in the sample?
