The big eight and a big step

"What is eight electronic rules?" Conrad asked curiously, despite the word of rule.

"Do you remember the eight hands of the Noble gases?" The old man asked.

"They look like stubborn octopuses."

"You are right!" K.O. laughed. "But every other element want to look like them."

"Could they?" Valerie asked doubtfully. "They are so very different! Not only in relation to the noble gases, but also in relation to each other!"

"They all have their own strategy for reaching the structure of the Noble gases." Elie noted." You already know how metals look, don't you?"

"They are making jelly from their plus hands." Conrad replied. "The plus hands are juggling with the remaining parts of the atoms."

"To say it official, metal atoms give off their valence electrons, creating an electron cloud of the delocalized electrons. Only the cations, which already has a noble gas structure, remains. But the cations share the free electrons among each other, so they don't really discard them." Elie said. "It is the first strategy."

"It is called metallic bond." K.O. said, and the twins nodded. The had already knew. "It is available among metals, on the left side of the BAt line."

"It means, the elements of the I. A, the II. A and the III. A could do that."

"What about the IV. A group?" Valerie asked. "I know that the Carbon atoms could do halfway the metallic and the covalent bonds, but why couldn't they make clear metallic bonds?"

"Because they would need too much energy for giving all the four valence electrons. Three is the maximum. So Carbon atoms had to share electrons with other atoms."

"That's why they are making covalent bonds!" Conrad cheered up.

"You are right!" K.O. said. "Although it is valid only the right side of the BAt line in the case of IV. A group."

"The BAt line confuses everything." Valerie nodded.

"The V. A group's upper side is more clearer on the covalent side. Nitrogen and Phosphorus make covalent bonds almost every time. Could you tell me how much covalent bonds they make?"

"Three."Conrad stated simply, remembering the shape and the bonds of the white phosphorus.

"Good!" Eli praised him.

"But how does this come out at eight?" Valerie asked.

"Two electrons form a covalent bond. The atoms share those electrons, so the bond's electrons are counted on both sides."

"So do the two electrons count for one atom and the other too?" Valerie asked, and the adults nodded. "It sounds like cheating."

K.O. and Elie began laughing.

"But it works well. In the case of your earrings, this cheating created a very strong structure!" Elie told her.

"Wouldn't you want to take that bandage off yet?" K.O. asked, and waved toward the white stripe on Valerie's head. "It would be time to disinfect your ears."

"But let's take it off carefully, okay?" The little girl asked anxiously after some time of thinking.

"Okay." Elie nodded, and sat down next to Valerie. "Come on! Let's get this off!"

Elie carefully loosened the bandage, and get off from the girl's head, with the cooling gel packs.

"Your earlobes are just a little bit red." She said, and carefully touched her earlobes. "Don't hurt anymore."

"And we will vanish that blush too!" K.O. showed a small vial of which he placed two red drops on the perforated earlobes. "Your are ready!"

Valerie looked at her earrings on the screen of her hand device with satisfaction.

"They are really good!" She said contentedly.

"Did them worth the pain?"

"Yes. Definitely!" She smiled to the others. "Shouldn't we have chosen red instead? That would be fine too!" Valerie turned to Elie.

"Nope!" She shook her head. "When the redness of your ears passes, the blue color will look gorgeous on you!"

"Sure! But why is this liquid, we used for disinfection of my earlobes, red?"

"It contains Iodine molecules, from the VII. A group. The Iodine atom has three pairs of hands and one free hand. How many covalent bond Iodine needs to from a Noble gases' structure?"

"One!" The twins cried in unison.

"Yes. It needs to form only one covalent bond to have eight electrons."

"Who could say that in the VI. A group, the Sulfur atom how many covalent bonds have to form to have the eight electrons?"

"It has two pairs of electrons, and two free electrons, so it requires two more electrons to have eight electrons. So two covalent bonds it has to make." Conrad said, proudly.

"Easy, isn't it?" Elie asked, and the kids agreed. "Then there is nothing left, you can build molecules!"

"Building molecules?" Conrad asked suspiciously, and looked around. "There isn't a single little one here!"

"I didn't mean in physically, but you could draw them now. The structures of them could be drawn."

"Drawing structures of molecules?" Valerie gulped a big, because she remembered the cursed question about the structure of Methane and a chalk, and a blackboard…

"Yes. It the piece of cake for you now!" She smiled at the tensed children. " For example the Iodine molecule is consist of two Iodine atoms. The sum formula is I2."

"But how could we draw the structure of the molecule?" Valerie asked shyly.

"At first we have to draw the atoms, and draw around the valence electrons."

She grabbed the branch, which was thrown away by Conrad, and wrote two big I into the sand.

"Then you have to write the valence electrons around them."

"How?"

"With points around them. As if they were in a square. Bottom-top and two sides. Iodine has seven valence electrons, so one point each, that's four of them."

"We have three valence electrons remained." Conrad said.

"Write next to the others." She gave the branch back to Conrad. " Two electrons hold each other, so draw a line instead of two points."

"It looks like, they would be in a glass!"Valerie said.

"With a slice of lemon." Conrad nodded.

"Two lemon slices make a covalent bond, which connects the two atoms together." Elie said, and draw a line between the two atoms. "Tadaaa! Here is the Iodine molecule!"

"It is not difficult after all..." Conrad looked at his sister hesitantly.

Elie and K.O. was looking at them expectantly, but neither of the twins wanted to draw a molecule.

"What's the problem?" Elie asked, because she wanted to give a light push to the twins.

"It was the last question on THAT exam." Valerie confessed.

"Should you have drawn the structure of the iodine molecule?"

"No." The girl shook her head.

"Which one was then?"

"Methane." Conrad mumbled.

The two adults tried to be serious, but inside they both were laughing hard. It was so cute, that Valerie and Conrad were still afraid of drawing the Methane molecule, after they were making a ton of them.

"Why don't you overcome your fear?" K.O. asked, and sat down to the sand. The kids looked at him, and their eyes were telling everything. They were too nervous to draw the Methane molecule, because of the former shock. "Do you remember the sum formula of Methane?"

"CH4" Valerie replied in a low voice.

"What does that mean?" Elie asked.

"The molecule is consist of one Carbon atom and four Hydrogen atoms." Conrad replied that time.

"So we just write them." She wrote one C and four H letters in a line. "Could you draw the valence electrons around them?" She asked the boy.

Conrad nodded, and put one point to each of the H-s, and four ones around the C letter.

"Good!" K.O. nodded, but this time Conrad didn't smile back. "How many electrons need the Carbon atom to get eight of them?"

"Four."Valerie said.

"The Hydrogen atoms only need one more each." Elie began to explain.

"Why?"

"Because the closest Noble gas is Helium, and Helium is stable with only two hands. So Hydrogens are stable with two electrons, not eight."

"Now, you just have to connect the free electrons, forming pairs." K.O. gave the branch to Valerie.

She hesitantly connected the dots.

"Don't make pairs with the Hydrogen atoms!" K.O. warned the girl. " If two of them is forming a molecule, there won't be enough electron for the Carbon atom! Just delete the line, and draw them to the Carbon atom. Good!" He praised Valerie.

"The methane molecule didn't quite look like this ... " Conrad criticized the drawing.

"It still needs to be refined a bit on the sketch."K.O. nodded.

"The electrons have negative charge, so they repel each other. Therefore, they are located as far apart as possible from each other. Draw the Hydrogens around the Carbon atoms!"

Valerie drew the Hydrogens on both sides and the up and down of the Carbon atoms. She draw line between the atoms.

"It is still doesn't look like the Methane molecule, but it begins to resemble."

"It is because we draw them in two dimension, but they exist in three dimension." Elie shrugged.

Valerie called a methane molecule from her hand device, and tried to see that like the drawn structure.

"If you hold it like this, it's quite the same!" She handed the molecule to her brother.

"Yes, you are right." Conrad said, when he realized, what did Valerie say. From a certain angle, the molecule of Methane looked exactly like the drawn picture.

"Okay, could you try to draw the structure of NH3?"Elie asked them, and the twins picked the branches, and tried to draw the structure of the molecule.