What does an increase in shell number an increase in shell number n

What is the formula for number of electrons within that shell?

how many orbitals can fit into the s/p/d/f-subshell?

how many electrons can fit in orbitals of the s/p/d/f sub-shell?

Why must electrons have opposite spin in an orbital?

So, in one energy level there are multiple subshells.

Blocks and the periodic table

What occurs to D-block elements 3d sub-shell energy level when the 3d shell is filled?

So order of emptying filling in d-block?

Ionic melting and boiling points

Solubility

Electrical conductivity

Covalent bonding

Why can boron only for 3 bonds?

Sulphur bonding