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प्रश्न
Define the following term with an example.
Element
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उत्तर
Element: It is a substance that cannot be broken down into simpler substance by chemical means
Ex.: Oxygen, Hydrogen, Gold & Helium.
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संबंधित प्रश्न
TRUE \ FALSE
Neils Bohr gave the theory to explain the arrangement of protons in an atom.
Write the names of the elements present in the:-
Acetic acid
Write the names of `"Ca"("NO"_3)_2` compounds :
State Dalton’s atomic theory.
Fill in the blank
A deficiency of electrons produces a ________ charge.
What is the usual symbol for (a) and electron (b) a proton, and (c) a neutron?
What are the building blocks of matter ?
Dalton's atomic theory says that atoms are indivisible. Is this statement still valid ? Give reasons for your answer.
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?
How many atoms are there in exactly 12 g of carbon-12 element ? (C = 12 u)
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)
The electron shell ______ is nearest to the nucleus.
Draw the diagrams representing the atomic structures of the following: Neon
Draw the basic structure of an atom representing its –
- Subatomic particles
- Nucleus
- Orbits or shells.
The basic unit of matter is ______.
State true or false. If false, correct the statement.
The basic unit of an element is molecule.
Name the sub-atomic particles.
Define the following term with an example.
Compound
The volume occupied by 4.4 g of CO2 at S.T.P ______
