
⭐ Elements in which the last electron enters any one of the five d-oribitals of their respective penultimate shells are called as <u>d-block</u><u> </u><u>elem</u><u>ents</u> .
⭐ But the last electron of Zn , Cd , Hg and Cn enters in the s-oribital of their respective ultimate shells rather than the d-oribitals of their respective penultimate shells . Therefore, these elements cannot be regarded as d-block elements .
☃️ But properties of these elements resemble to the d-block elements rather than s-block elements .
☃️ Therefore, to make the study of periodic classification of elements more rational, they are studied along with d-block elements .
✍️ Thus <u>on the basis of properties</u> all transition elements are d- block elements, but <u>on the basis of electronic configuration</u> all d -block elements are not transition elements .
Answer:
The first is the empirical formula which shows you the number of different atoms in the compound. After you convert the grams of each element into moles, you calculate the ratio of the moles, which gives you the ratio of the elements in the compound. More number-crunching gives you the molecular formula.
Synthesis reaction is a reaction where two or
more substances combine to form a new compound. <span>It
is a reaction which releases energy in the form of heat and light. Therefore,
it is an exothermic reaction. </span>From its the definition the correct answer is the third option where carbon dioxide and water combine to form carbonic acid.
Halogens can be characterized as :
1) High Electronegativity
2) Low melting & boiling points
3) Forms Ionic compounds
4) Non-metallic in nature
Hope this helps!
x is the chemical symbol of the element and it must correspond to the atomic number