Home
Class 9
CHEMISTRY
Helium atom has an atomic mass of 4 u an...

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

A

1

B

2

C

4

D

3

Text Solution

Verified by Experts

The correct Answer is:
B
Atomic mass = No. of protons + No. of neutrons
So, 4 = 2 + No. of neutrons
And, No. of neutrons = 4 - 2
= 2
Thus, the helium atom has 2 neutrons.
Promotional Banner

Topper's Solved these Questions

  • STRUCTURE OF ATOM

    LAKHMIR SINGH & MANJIT KAUR|Exercise Exercise|203 Videos

  • STRUCTURE OF ATOM

    LAKHMIR SINGH & MANJIT KAUR|Exercise Very Short Answer|1 Videos

  • MODEL TEST PAPER 5

    LAKHMIR SINGH & MANJIT KAUR|Exercise Section B|2 Videos

Similar Questions

Explore conceptually related problems

Helium atom has an atomic mass of 4u and two protons in its nucleus. How many neutrons does it have ?

Lithium atom has atomic mass 6 and has 3 protons in it nucleus. How many neutrons does it have? Write down its electronic configuration.

Which atom does not have any neutron in the nucleus and why?

(a) What is mean by (i) atomic number, and (ii) mass number, of an element ? Explain with the help of an example (b) What is the relation between the atomic number and mass number of an element ? (c) If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain ?

The atomic number of sodium is 11. How many protons are there in the nucleus of sodium atom ? How manu electrons does an atom of sodium contain ? How many electrons and protons does an ion of sodium which has a charge of +1 contain ?

An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon ?

LAKHMIR SINGH & MANJIT KAUR-STRUCTURE OF ATOM-Value Based Questions
  1. Helium atom has an atomic mass of 4 u and two protons in its nucleus. ...

    Text Solution

    |

  2. Ajay and Rakesh live in Rajgarh town of Churu districk of Rajasthan. A...

    Text Solution

    |

  3. Roshni is a student of class IX in a school in Delhi. One day Roshni's...

    Text Solution

    |

  4. Vibha is a student of 9th standard. Vibha's family has an LPG connecti...

    Text Solution

    |

  5. (a) (i) Ethyl mercaptan (ii) Strong smell of ethyl mercaptan (b) D...

    Text Solution

    |

  6. Abhinav is a student of class IX. One day all the students were perfor...

    Text Solution

    |

  7. All the students of class 9 were performing experiments to study the t...

    Text Solution

    |

  8. Raghvan is a student of class 9 in a Chennai school. His teacher, Mr. ...

    Text Solution

    |

  9. Rohit and Arun are two friends both of whom study in class IX in diffe...

    Text Solution

    |

  10. Bhavna is a student of class IX in a city school. She has a five year ...

    Text Solution

    |

  11. Bunny is a ten year old boy. His motherm Mrs. Bhatia, is having high f...

    Text Solution

    |

  12. Pawan is a student of class IX. The students of his class have recentl...

    Text Solution

    |

  13. One day Vabhav was performing experiments in the science laboratory ba...

    Text Solution

    |

  14. Pratap is a student of class IX in a city school. He has recently stud...

    Text Solution

    |

  15. Vikram is a student of class IX in a village school. He lives on the o...

    Text Solution

    |

  16. Ramnik is a student of class 9. One day he was studying a chapter of c...

    Text Solution

    |

  17. Naveen is a student of class IX in a city school. His uncle Ram Dev wh...

    Text Solution

    |

  18. Akshay and Sauranh are the students of class IX. They have recently st...

    Text Solution

    |