What is the atomic number and mass number of A3+ ion with 21 electrons and 25 neutrons?


Number of protons = 21 + 3 = 24
Atomic number = 24
Mass number = No. of protons + No. of neutrons
= 24 + 25 = 49.

154 Views

Define isotopes, isobars and isotones.


Isotopes: Isotopes are atoms of the same element having same atomic number but different mass numbers. e.g. 

Isobars: Isobars are atoms of different elements having different atomic numbers but the same mass number. e.g.  are isobars of each other. 

Isotones: Isotones are atoms of different elements having same number of neutrons. For example 

695 Views

Advertisement

Mass number of an element is 27 and number of protons is 13. Calculate the number of electrons, neutrons and atomic number.


Here number of protons = 13
Number of electrons = 13
Atomic number = Number of protons = 13
Number of neutrons = Mass No. (A) - At. No. (Z) = 27- 13= 14

108 Views

Advertisement

Name different isotopes of hydrogen. Give their atomic numbers and mass numbers.


Hydrogen has three isotopes namely protium, deuirium and tritium.

 height=
134 Views

Explain that atomic number is the fundamental property of an element.

All atoms of the same element have same number of protons in their nuclei. Therefore, atoms of the same elements have same atomic number. However, atoms of different elements have different atomic numbers because their nuclei have different number of protons. Thus, atomic number of each element has certain characteristic value and no two elements have the same atomic number. Therefore, atomic number of an element is a fundamental property.
351 Views

Advertisement