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प्रश्न
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?
उत्तर
(a) Its atomic number is 3.
(b) Mass no. = 3 + 4 = 7
\[{\underset{2}{\text{ K }}\underset{8}{\text{ L }}}\]
(c) Electronic configuration is(d) Element E is a metal because in order to complete its octet, the element loses 1 electron from its outermost orbit and attains a stable configuration with 2 electrons in its first shell. Elements which lose electrons to attain stability are called metals.
(e) A Cation will be formed by an atom of element A because its outermost single electron can be easily donated.
(f) E+
(g) Element X is lithium.
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संबंधित प्रश्न
Why is it not possible to see an atom with naked eyes?
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Name the particle or particles you would expect to find in :
The nucleus of an atom
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is the atomic numebr of X ?
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The electron shell ______ is nearest to the nucleus.
Select the correct answer to the statement given below:
The basic unit of matter is not capable of independent existence.
Select the correct answer to the statement given below:
Imaginary path around the nucleus of an atom in which electrons revolve.
The basic unit of matter is ______.
The smaller particles found in the atom is called ______.
Project.
To have an idea of what atoms are, students can be asked to construct atoms using pipe cleaners (thin metal wires-electron shells), pompoms (balls-different colours for protons and neutrons) and beads (electrons). Students will love and enjoy putting them together and they look great hanging from the ceiling in the classroom.
Define the following term with an example.
Metal
Define the following term with an example.
Non-metal
Atoms of different elements having ______ mass numbers, but ______ atomic numbers are called isobars.
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
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