English

Define : Atomic Number

Advertisements
Advertisements

Question

 Define: Atomic number

Definition
Advertisements

Solution

Atomic number : Number of protons present in the nucleus of an atom.

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Atoms, Molecules and Radicals - Additional questions

APPEARS IN

Selina Concise Chemistry [English] Class 7 ICSE
Chapter 4 Atoms, Molecules and Radicals
Additional questions | Q 21.2

RELATED QUESTIONS

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


Give the name of the element present in the following compound: 

Hydrogen bromide


Define: Atomic number


What is meant by atomicity ? Explain with two examples.


What do the following denote ?

  1. N
  2. 2N
  3. N2
  4. 2N2

What is the difference between the molecule of an element and the molecule of a compound? Give one example of each.


Work out the formula for magnesium hydrogencarbonate.


What are (i) ionic compounds, and (ii) molecular compounds ? Give two examples of each type of compounds.


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.


Give one example of a triatomic molecule


Give one example of a polyatomic molecule.


Give a reason why –

Helium is considered monoatomic, but hydrogen a diatomic molecule.


State the atomicity of the following:

Chlorine


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.


Classify the following molecules as the molecules of element or compound

1.  
2.  
3.  
4.  

Give any two examples for heterodiatomic molecules.


Derive the relationship between Relative molecular mass and Vapour density.


Which of the following contains maximum number of molecules?


Write any two classifications of a molecule.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×