engineering recuitment DRDO CEPTAM STA B Tier I (Sr. Technical Assistant) Mock Test 2022 General Science Chemistry Periodic Table
An element 'X' is present in 15th group and 3rd period of periodic table. If the mass number of an isotope of this element is 33, what is the number of neutrons present in an atom of that isotope?
1
18
2
15
3
13
4
20