https://www.assignmentpoint.com/science/biology/micromeritics.html http://alcromosoma.blogspot.com/2018/07/laporan-praktikum-kimia-dasar-ikatan.html https://www.slideshare.net/elfisusanti/reaksi-eliminasi-1961874 http://faradillahmaulina.blogspot.com/2016/02/reaksi-eliminasi.html http://imamafdolhakikitugas.blogspot.com/2013/10/v-behaviorurldefaultvmlo.html http://www.guruamir.com/2020/02/contoh-soal-asesmen-kompetensi-minimal.html https://belajarkimiaonlineyuk.wordpress.com/2013/08/19/bentuk-orbital/ https://docplayer.info/51029647-Pengembangan-media-pembelajaran-interaktif-berbasis-teknologiaugmented-reality-pada-materi-ikatan-kimia-skripsi.html sifat keperiodikan unsur: https://www.youtube.com/watch?v=HoZABeOC9mk (Ibu2) https://www.youtube.com/watch?v=JZgu0mHmeTE https://www.youtube.com/watch?v=J-SQ2fJud7Y https://www.youtube.com/watch?v=8Rz-10-gkdw&t=153s https://www.studiobelajar.com/sistem-periodik-unsur/ (apik iki)