Advertisements
Advertisements
Question
Explain the Mass number with example.
Advertisements
Solution
The mass number of an element is equal to the sum of the number of protons and the number of neutrons present in it.
Example: Number of protons in carbon = 6
Number of neutrons = 6
Hence mass number = Number of protons + Number of neutrons
= 6 + 6
= 12
APPEARS IN
RELATED QUESTIONS
Fill in the blanks- The number of protons in the nucleus of an atom is called its ....................
State the main postulates of Dalton’s atomic theory.
If an atom ‘A’ has mass number 35 and atomic number 17, state the number of protons, electrons and neutrons it contains.
What is atomic number?
Complete the following table.
| Atomic Number | Mass Number | Number of Neutrons | Number of Protons | Number of Electrons | Name of the Element |
| 9 | ______ | 10 | ______ | ______ | ______ |
| 16 | ______ | 16 | ______ | ______ | ______ |
| ______ | 24 | ______ | ______ | 12 | Magnesium |
| ______ | 2 | ______ | 1 | ______ | ______ |
| ______ | 1 | 0 | 1 | 1 | ______ |
The No. of electrons in the outermost shell of the atom of an inert gas ______.
Mass No. 27 is for the element ______.
Electrons revolve around the nucleus in definite open shells.
Compare the charge and mass of protons and electrons.
Ca2+ has completely filled outer shell. Justify your answer.
