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प्रश्न
Define: Mass number :
उत्तर
Mass number : Numbr of protons and neutrons present in the nucleus of an atom.
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संबंधित प्रश्न
Write down the name of a compound represented by the following formula:
K2SO4
Give the name of the element present in the following compound:
Potassium sulphate
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
Define: Atomic number
Define: Atomic number
What is meant by atomicity ? Explain with two examples.
What is the atomicity of the following ?
- Oxygen
- Ozone
- Neon
- Sulphur
- Phosphorus
- Sodium
In what form does oxygen gas occur in nature ?
What do the following denote ?
- N
- 2N
- N2
- 2N2
One of the forms of a naturally occurring solid compound P is usually used for making the floors of houses. On adding a few drops of dilute hydrochloric acid to P, brisk effervescence are produced. When 50 g of reactant P was heated strongly, than 22 g of a gas Q and 28 g of a solid R were produced as products. Gas Q is the same which produced brisk effervescence on adding dilute HCl to P. Gas Q is said to cause global warming whereas solid R is used for white-washing.
- What is (i) solid P (ii) gas Q, and (iii) solid R.
- What is the total mass of Q and R obtained from 50 g of P ?
- How does the total mass of Q and R formed compare with the mass of P taken ?
- What conclusion do you get from the comparison of masses of products and reactant ?
- Which law of chemical combination is illustrated by the example given in this problem ?
Work out the formula for magnesium hydrogencarbonate.
The cation of an element has :
Molecular compounds are usually formed by the combination between :
An element X forms the following compounds with hydrogen, carbon and oxygen :
H2X, CX2, XO2, XO3
State the three valencies of element X which are illustrated by these compounds.
Calculate the mass of 3.011 × 1024 atoms of carbon.
Correct the following statement:
A molecule of sulphur is monoatomic.
Give one example of a triatomic molecule
Give one example of a polyatomic molecule.
Give a reason why –
Ozone is considered triatomic, but phosphorus a tetratomic molecule.
State the atomicity of the following:
Argon
State the atomicity of the following:
Sulphur
State true of false. If false, give the correct statement.
NaCl represents one molecule of sodium chloride.
The Atomicity of phosphorous is ______
Give any two examples for heterodiatomic molecules.
