Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one :
has four electrons in the valency shell ?

Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one : forms an anion

Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one : forms a cation

Three elements 'X', 'Y' and 'Z' have atomic numbers 18, 19 and 20 respectively. How many electrons are present in the M shell of these elements?

The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belongs to the same group ?

Three elements X , Y and Z have atomic numbers 19 , 37 and 55 respectively . Then the correct statement (s) is / are

Four elements P, Q, R and S have atomic numbers 12, 13, 14 and 15 respectively. Answer the following questions giving reasons: (i) What is the valency of Q ? (ii) Classify these elements as metals and non-metals. (iii) Which of these elements will form the most basic oxide?

The following species has the lowest number of electrons in the valence shell

Set of elements having one electron in their valence shell is :-

The atomic number of an element is 17. The number of orbitals containing electron pairs in the valence shell is:

The atomic number of an element is 15. The number of orbitals containing electron pairs in the valence shell is: