Here we are publishing 50 most imortant focus point to remember from kerala SSLC Chemistry-chapter 1 periodic-table-and-electronic-configuration
SHELLS & SUBSHELLS
⏺️In an atom there are main energy level called shells and sub energy levels called sub shells.
⏺️The number of sub shells in each energy level is equal to its shell number.
🔅s sub shells can accommodate 1 to 2 electrons
🔅p sub shells can accommodate 1 to 6 electrons
🔅d sub shells can accommodate 1 to 10 electrons
🔅f sub shells can accommodate 1 to 14 electrons
🌟1s
🌟1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s………………….
🌟The electrons in an atom are distributed in the increasing order of the energies of sub shells. This is called sub shell electronic configuration.
🌟The maximum number of electrons accommodated in each sub shells s-2, p-6, d-10, f-14.
HOW TO FIND BLOCKS AND GROUP NUMBER
BLOCK OF ELEMENT
✴️Block of elements= The sub shell to which the last electron is entered
✴️Half filled d sub shells are more stable.
✴️Completely filled d subsheel are more stable.
Group Number
▶️s block elements No of electrons in the last s sub shell
▶️p block elements No of electrons in the last p sub shell +12
▶️d block elements No of electrons in the last s sub shell + No. of electrons in the inner d sub shell.
P BLOCK ELEMENTS
*️⃣ 13 to 18 group elements are present in p Block
*️⃣1 to 6 electrons are present in p subshell
*️⃣Elements in the solid, liquid and gaseous state at room temperature are included in this block
*️⃣In p block elements , less reactive elements(more stable
elements) are present in the 18
th group (Noble gases)
*️⃣Elements with Positive and negative oxidation state are present in p block
*️⃣P block elements usually show higher ionization energy than the s block elements.
*️⃣In p block elements, the highly reactive elements are
D BLOCK ELEMENTS
💠Groups 3 to 12 belongs to ‘d’ block elements of periodic table
💠From 4 the period onwards the ‘d’ block elements beigns.
💠‘d’ block elements are called transition elements
💠The last electron is filled in the penultimate shell
💠The group number of the ‘d’ block elements will be the same as the sum of electron in the outer most ‘ s’ subshell and inner ‘d’ sub shell ‘d’ block elements are called transition elements
CHARACTERSTICS
💠They show different oxidation state
💠They form coloured compounds
💠The last electron is filled in the penultimate shell
💠They show similarities in properties not only in group but also in period
💠Most of them are metals
💠Most of the coloured salts are compounds of
transition elements.
💠The colour is due to the presence of transition metals ions present in these compounds.
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