Advertisements
Advertisements
प्रश्न
Define: Mass number :
उत्तर
Mass number : Numbr of protons and neutrons present in the nucleus of an atom.
APPEARS IN
संबंधित प्रश्न
Write down the name of a compound represented by the following formula:
KNO3
Write down the name of a compound represented by the following formula:
CaCO3
Give the name of the element present in the following compound:
Baking powder
State the term.
The number of atoms present in a molecule of an element _________
Define: Atomic number
Define: Atomic weight :
What is the atomicity of the following ?
- Oxygen
- Ozone
- Neon
- Sulphur
- Phosphorus
- Sodium
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 :
Correct the following statement:
A molecule of sulphur is monoatomic.
Why are the symbols and formulae of substances important?
Give one example of a polyatomic molecule.
State the atomicity of the following:
Neon
State the atomicity of the following:
Chlorine
Which of the following is a short and scientific way of representing one molecule of an element or compound?
State true of false. If false, give the correct statement.
NaCl represents one molecule of sodium chloride.
Classify the following molecules as the molecules of element or compound
| 1. |  |
|
| 2. |  |
|
| 3. |  |
|
| 4. |  |
Which of the following is a triatomic molecule?
Two elements sometimes can form more than one compound.
Define: Atomicity.
Which of the following contains maximum number of molecules?
