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A. PERKEMBANGAN DASAR PENGELOMPOKKAN UNSUR-UNSUR DALAM SPU.

1. Lavoiser . ........................................................................................................................... .................... ............................................................................................................................................................... .. ............................................................................................................................. .................................... ............................................................................................................................. ....................................

2. Triade Dobereiner ................................................................................................................................................................ ............................................................................................................................. ................................... ............................................................................................................................. ................................... ................................................................................................................................................................ ............................................................................................................................. ................................... ................................................................................................................................. ............................... Tabel 1. Contoh Pengelompokan Sifat Unsur Berdasarkan Triade Dobereiner [1]

Triade A r Rata-rata Ar Unsur Pertama dan Ketiga

Wujud

Klorin Bromin Iodin

35,5 79,9 127

(35,5 + 127) / 2 = 81,2

Gas Cair Padat

Tabel 2. Daftar Unsur Triade Dobereiner [1]

Triade 1 Triade 2 Triade 3 Triade 4 Triade 5

Li Ca S Cl Mn

Na Sr Se Br Cr

K Ba Te I Fe

Sumber : Brown & Le May, 1977

Benarkah pernyataan yang dikemukakan Dobereiner? Untuk membuktikannya, ujilah teori Triade Dobereiner tersebut menggunakan tabel massa atom berikut.

Tabel 3. Massa Atom Beberapa Unsur

No

Unsur Massa Atom

1 Litium 7

2 Natrium 23

3 Kalium 39

4 Kalsium 40

5 Stronsium 88

6 Barium 137

7 Klorin 35

8 Bromin 80

9 Iodin 127

10 Belerang 32

11 Selenium 79

12 Tellurium 128

Sumber: www. elementmultidict.com

MODUL - 5 SISTEM PERIODIK UNSUR-UNSUR &

SIFAT-SIFAT UNSUR DALAN SPU

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3. Hukum Oktaf ............................................................................................................................. ................................... ................................................................................................................................................................ ............................................................................................................................. ................................... ................................................................................................................................................. ............... ................................................................................................................... ............................................. Contoh : Hukum Oktaf

4. Dmitri Ivanovich Mendeleev ............................................................................................................................. ......................................... ............................................................................................................................. ......................................... ................................................................................. ..................................................................................... ............................................................................................................................. ......................................... ................................................................................................................................ ...................................... ............................................................................................ .......................................................................... ............................................................................................................................. ......................................... ........................................................................................................................................... ........................... ....................................................................................................... ...............................................................

Contoh: SPU Mendeleev

5. Sistem Periodik Modern

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B. SIFAT-SIFAT UNSUR DALAM SPU

Sistem periodic unsur-unsur yang sekarang terdiri dari : 114 Unsur Jumlah Periode ada 7 dan 2 golongan ( A dan B ) Jumlah golongan A di mulai dari IA – VIII A Jumlah golongan B IB – VIII B Jumlah golongan transisi dalam ( Lantanida & Aktinida ) Yang wajib anda pahami ada 5 sifat-sifat unsur dalam SPU, antara lain :

1.JARI-JARI ....................................................................................................................................................... ..................... ............................................................................................................. .................................................................... ............................................................................................................................. .................................................... ...................................................................................................................................... ........................................... ....................................................................................... .......................................................................................... ............................................................................................................................. .................................................... ............................................................................................................................. ....................................................

BAGAIMANA DENGAN JARI-JARI ATOM ION ? Jawab : ................................................................................................................................................. ...............................

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2. ENERGI IONISASI ............................................................................................................................. .................................................

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DATA :

Ionisasi I : Be(g) + 899 kJ Be+(g) + e

Ionisasi II: Be+(g) + 1757 kJ Be2+(g) + e

Ionisasi III: Be2+(g) + 14848 kJ Be3+(g) + e

Ionisasi IV: Be3+(g) + 21006 kJ Be4+ + e MENGAPA IONISASI 1 LEBIH KECI DARI IONISASI 2, DAN SETERUSNYA ?....... Jawab : .................................................................................................................................................. .............................

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3. AFINITAS ELEKTRON:

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4. KEELEKTRONEGATIFAN :

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5. LOGAM DAN NON LOGAM ............................................................................................................................. ......................................

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6. KEREAKTIFAN

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