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
If number of electrons in an atom is 8 and number of protons is also 8, then
- What is the atomic number of the atom? and
- What is the charge on the atom?
Dalton said that ______ could not be divided.
Tick the most appropriate answer.
Which of these have similar chemical properties but different set of physical properties and mass number?
- isobars
- elements
- isotopes
- none of these
Fill in the following blanks in respect of an atom of an element
| No. of protons | No. of neutron | Mass number | Atomic number | No. of electrons | Symbol |
| 11 | 12 | ___________ | ___________ | ___________ | ________ |
The diagram represents an isotope of hydrogen [H]. Answer the following:

Atomic no. = 1
Mass no. = 1
Are isotopes atoms of the same element or different elements.
Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:
- forms anion – negative ion;
- forms cation – positive ion;
- has 4 electrons in the outermost orbit. [Y, Z, X]
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
What is common salt? Name the elements present in it. Write the formula of common salt. What are the atomic number and the mass number of the elements? Write the ions in the compound.
What is mass number of an atom?
The Atomic number of an element is 20. It has ______ valence electrons.
