मराठी
सी.आई.एस.सी.ई.आयसीएसई ICSE Class 7

Define : an Atom: - Chemistry

Advertisements
Advertisements

प्रश्न

Define: An Atom:

व्याख्या
Advertisements

उत्तर

An Atom: Smallest particle of an element that can exist and have properties of an element.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Atoms, Molecules and Radicals - Additional questions

APPEARS IN

सेलिना Concise Chemistry [English] Class 7 ICSE
पाठ 4 Atoms, Molecules and Radicals
Additional questions | Q 21.1

संबंधित प्रश्‍न

If bromine atom is available in the form of, say, two isotopes `""_35^79Br (49.7%)" and """_35^81Br (50.3%)`, calculate the average atomic mass of bromine atom.


Tick the most appropriate answer.

Who discovered that radioactive rays are given out by uranium?

  1. Henri Becquerel
  2. Marie Curie
  3. Pierre Curie
  4. Schmidt

TRUE \ FALSE

Cathode rays are a stream of fast moving particles that travel in random directions.


WRITE SHORT ANSWER

What is radioactivity?


Name two particles found inside the nucleus. What are they collectively called ?


Name the particle or particles you would expect to find in :

The orbit of an atom


A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.

What is the mass number of X?


Fill in the blank

If an atom loses an electron, it acquires ______ a charge.


Fill in the blank

A charged particle is called an _____


Name the three subatomic particles present in an atom.


Draw diagrams representing the atomic structures of the following:

  1. Sodium atom
  2. Chlorine ion
  3. Carbon atom
  4. Oxygen ion

The smallest particle of matter that can exist by itself is ______.


Assertion: An atom is electrically neutral.

Reason: Atoms have equal number of protons and electrons.


Define the following term with an example.

Non-metal


Which of the following statements made by Dalton has not undergone any change?


Atoms of different elements having ______ mass numbers, but ______ atomic numbers are called isobars. 


A change in the physical state can be brought about


Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order

  1. Rutherford’s atomic model
  2. Thomson’s atomic model
  3. Bohr’s atomic model

Lead is also known as plumbum.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×