Advertisements
Advertisements
प्रश्न
Define: Atomic weight :
Advertisements
उत्तर
Atomic weight : It is the ratio that tells how many times an atom of an element is heavier than atom of Hydrogen
APPEARS IN
संबंधित प्रश्न
Write down the name of a compound represented by the following formula:
Al2(SO4)3
Write down the name of a compound represented by the following formula:
CaCl2
Write down the name of a compound represented by the following formula:
CaCO3
Give the name of the element present in the following compound:
Hydrogen bromide
Give the name of the element present in the following compound:
Baking powder
Give the name of the element present in the following compound:
Potassium sulphate
State the term.
The number of atoms present in a molecule of an element _________
Define: Atomic number
Define: Mass number :
What is the atomicity of the following ?
- Oxygen
- Ozone
- Neon
- Sulphur
- Phosphorus
- Sodium
What is the difference between the molecule of an element and the molecule of a compound ? Give one
example of each.
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 ?
What are (i) ionic compounds, and (ii) molecular compounds ? Give two examples of each type of compounds.
The cation of an element has :
Molecular compounds are usually formed by the combination between :
An element A forms an oxide A2O5.
What is the valency of element A ?
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.
Correct the following statement:
A molecule of sulphur is monoatomic.
Explain the term – molecules. Give three examples of atoms of the same element forming a molecule. State the atomicity of the same.
State the main points of the contradiction of Dalton’s atomic theory by the Modern Atomic Theory.
Give a reason why –
Helium is considered monoatomic, but hydrogen a diatomic molecule.
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. |  |
Two elements sometimes can form more than one compound.
Write any two classifications of a molecule.
