@@ -2,7 +2,7 @@
title: 1
description:
published: true
date: 2026 - 02 - 11T15:36:13.726 Z
date: 2026 - 02 - 11T15:42:38.277 Z
tags:
editor: ckeditor
dateCreated: 2026 - 02 - 11T14:58:54.870Z
@@ -40,14 +40,13 @@ dateCreated: 2026-02-11T14:58:54.870Z
< / table >
< / figure >
< p > < / p >
< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Element< / span > < / h3 >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Protons = Electrons ⇒ Atom. Neutral.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Protons ≠ Electrons ⇒ Ion. Charged.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Electrons are surrounding the nucleus, consisting of protons and neutrons.< / span > < / p >
< p > < / p >
< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Element< / span > < / h3 >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Mass number are the number of protons and neutrons in the nucleus.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Atomic number are the number of protons in nucleus.< / span > < / p >
< p > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > For example, < sup > 4< / sup > < sub > 2< / sub > He, where mass number is written on top left, and atomic number on bottom left.< / span > < / p >
< p > < / p >
< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Periodic Table< / span > < / h3 >
@@ -130,8 +129,8 @@ dateCreated: 2026-02-11T14:58:54.870Z
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > g< / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 9< / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 18< / span > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< / tbody >
< / table >
@@ -175,9 +174,9 @@ dateCreated: 2026-02-11T14:58:54.870Z
< tbody >
< tr >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⇡⇣< / span > < / td >
< td style = "text-align:center;width:60px;" > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⇡⇣< / span > < / td >
< td style = "text-align:center;width:60px;" > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⇡⇣< / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⇡⇣< / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⇡⇣< / span > < / td >
@@ -190,13 +189,13 @@ dateCreated: 2026-02-11T14:58:54.870Z
< / tr >
< tr >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 1s< / span > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 2s< / span > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" colspan = "3" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 2p< / span > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 3s< / span > < / td >
< td style = "text-align:center;" > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" colspan = "3" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 3p< / span > < / td >
< / tr >
< / tbody >
@@ -205,27 +204,27 @@ dateCreated: 2026-02-11T14:58:54.870Z
< p > < / p >
< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Aufbau principle< / span > < / h3 >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > The lowest energy subshell or orbital will be filled first< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > 1s < 2s < 2p < 3s < 3p < 4s < 3d< / span > < br > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > 1s < 2s < 2p < 3s < 3p < 4s < 3d< / span > < br > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Imagine drawing a line from right to left.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > You should be able to find out that 4s subshell has a lower energy than 3d subshell this way.< / span > < br > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > You should be able to find out that 4s subshell has a lower energy than 3d subshell this way.< / span > < br > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / p >
< figure class = "table" >
< table >
< tbody >
< tr >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > n< / strong > < / span > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 1< / strong > < / span > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
@@ -235,67 +234,67 @@ dateCreated: 2026-02-11T14:58:54.870Z
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 1< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 1s< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 2< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 3< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 2< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 2s< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 2p < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 4< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 5< / strong > < / span > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 3< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 3s< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 3p < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 3d< / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 6< / strong > < / span > < / td >
@@ -303,13 +302,13 @@ dateCreated: 2026-02-11T14:58:54.870Z
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 7< / strong > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
@@ -317,61 +316,61 @@ dateCreated: 2026-02-11T14:58:54.870Z
< / tr >
< tr >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 4< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 4s< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 4p < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 4d< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 4f< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 8< / strong > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > < strong > 5< / strong > < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 5s< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 5p < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 5d< / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > 5f< / span > < / td >
< td > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< / tr >
< tr >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
< td > < / td >
< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
< td style = "text-align:center;width:60px;" > < span style = "font-family:Arial, Helvetica, sans-serif;" > ⁄ < / span > < / td >
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< td > < span style = "font-family:Arial, Helvetica, sans-serif;" > < / span > < / td >
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< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Pauli's E xclusion principle< / span > < / h3 >
< h3 > < span style = "font-family:Arial, Helvetica, sans-serif;" > Pauli's e xclusion principle< / span > < / h3 >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Each orbital can be occupied by no more than 2 electrons.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > If 2 electrons occupy the same orbital, they must have opposite spins.< / span > < / p >
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@@ -388,4 +387,6 @@ dateCreated: 2026-02-11T14:58:54.870Z
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Group 17 (7) - Halogen< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Group 18 (8) - Noble gas< / span > < / p >
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< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Noble gases are stable in atomic form because the outermost shell are fully filled.< / span > < / p >
< p > < span style = "font-family:Arial, Helvetica, sans-serif;" > Other element tend to lose, gain or share electron to achieve nearest fully filled electronic structure, that is duplet or octet structure.< / span > < / p >
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