Tag: atomic theory of dalton

Questions Related to atomic theory of dalton

______ are the smallest unit of matter that can take part in a chemical reaction.

  1. Molecules

  2. Compounds

  3. Atoms

  4. Electrons


Correct Option: C
Explanation:

Dalton's atomic theory states that atoms are the smallest unit of matter that can participate in a chemical reaction. Chemical reactions involve the combination, separation, or rearrangement of atoms, but atoms are neither created, destroyed, divided into parts, or converted into atoms of any other kind.

Dalton's theory fails to determine the existence of

  1. molecules

  2. compounds

  3. allotropes

  4. All of the above


Correct Option: C
Explanation:

Dalton's atomic theory fails to explain the existence of allotropes; it does not account for differences in properties of charcoal, graphite, diamond.

According to Dalton, atoms of different elements combine with one another to form :

  1. compounds

  2. elements

  3. solution

  4. All of the above


Correct Option: A
Explanation:

 According to Dalton, atoms of different elements combine with one another to form compounds.

Dalton had suggested that an atom is indivisible. 

  1. True

  2. False


Correct Option: A
Explanation:

Dalton had suggested that an atom is indivisible. All matter is composed of elements, which in turn are made up of small indivisible particles called atoms.

Which of the following is a postulate of Dalton's atomic theory?

  1. All matter consists of indivisible particles called atoms

  2. The atom is the smallest unit of matter that can take part in a chemical reaction

  3. Atoms of same element can combine in more than one ratio to form two or more compounds

  4. All of the above


Correct Option: D

Dalton's theory of same element have same mass and properties was proved wrong with the invention of:

  1. molecules

  2. isotopes

  3. neutrons

  4. compounds


Correct Option: B
Explanation:

According to Dalton Atomic Theory, atoms of an element are identical in mass, size and many other chemicals or physical properties. 


But, practically we observe that atoms of several elements differ in their densities and masses. 

These atoms with the different masses are known as isotopes. For example, Chlorine (Cl) has 2 isotopes with the mass numbers of 35 and 37.

Hence, the correct option is $\text{B}$

A/An______ is the smallest particle of a substance which can take part in a chemical reaction.

  1. atom

  2. molecule

  3. both A and B

  4. none of the above


Correct Option: A
Explanation:

An atom is the smallest particle of a substance which can take part in a chemical reactions.

Various theories were put forth to study the nature of atom. The main postulates of Dalton's atomic theory are :

  1. all matter are composed of atoms

  2. all matters are composed of molecules

  3. all atoms of an element are identical.

  4. the atoms of different elements vary in size and mass.


Correct Option: A,C,D
Explanation:

It was John Dalton who firstly developed a theory on the structure of matter, later on which is known as Dalton's atomic theory.


DALTON'S ATOMIC THEORY :

1. Matter is made up of very small undivisible particle called atoms.
2. All the atoms of a given element is identical in all respect i.e. mass, shape, size, etc.
3. Atoms cannot be created nor destroyed by any chemical process.
4. Atoms of different elements are different in nature.

Dalton suggested that atoms were indestructible and unchangeable to explain:

  1. why mass is conserved in chemical reactions.

  2. why elements combine in fixed weight ratios to form compounds.

  3. why elements are characterized by the mass of their atoms.

  4. why compounds combine in fixed weight ratios in chemical reactions.


Correct Option: A
Explanation:

Atoms cannot be subdivided, created or destroyed into smaller particles when they are combined,separated or rearranged in chemical reactions. The whole matter remains conserved in the form of reactants changing to products.

Which of the following is not a postulate of Dalton's atomic theory? 

  1. Different elements have atoms of different masses.

  2. Atoms combine in simple whole number ratios to form compounds..

  3. Atoms are not created or destroyed in chemical change.

  4. Atoms of a single element can have different masses.


Correct Option: D
Explanation:

Postulates of Dalton's atomic theory:

  • All matter consists of indivisible particles called atoms.
  • Atoms of the same elements are similar in shape and mass but differ from the atoms of other elements.
  • Atoms cannot be created or destroyed.
  • Atoms of different elements may combine with each other in a fixed, simple, whole number ratios to form compound atoms.
  • The atom is the smallest unit of matter that can take part in a chemical reaction.