Banks

I suggest adding Economics.

I have an idea, how about adding Economics category? Thanks for any considerations.

80+ degrees, really? Are you sure you're keeping the thermostat down? It has to be your room/house/apartment, not your devices.

Ok, So I've completed the question #8 from textbook. What I'm confused about is question #9. Here is the question 8. #8. For each substance below, identify it as ionic or molecular. Explain how you came to your conclusion. a) Compound 1: melting point: 48C, low solubility in water, flammable, mild odour, colourless solid easily crushed My answer: molecular - because of low melting point b) Compound 2: melting point: 800C, highly soluble, solution is highly conductive, hard, white crystals My answer: ionic - because of high melting point + tight crystal structure c) Compound 3: melting point: 185C, decomposes at 190C, highly soluble, solution is not conductive, hard, white crystals My answer: molecular - because it's not conductive + hard d) Compound 4: sublimates (goes from solid to gas) at -56C, moderately soluble in water, colourless, odourless My answer: molecular - because it's able to change from solid to gas + low melting point e) Compound 5: highly flammable liquid at room temperature, does not mix with water, less dense than water My answer: molecular - because it's liquid f) Compound 6: colourless, odourless liquid, tends to dissolve ionic substances, boils at 100C My answer: molecular - because it's liquid #9. All of the compounds in question 8 are common materials. Suggest the identity of each material from the descriptions of the physical properties. So, I have to suggest the identity? What kind of identities? Is it names such as coffee, water, cooking oil, table salt, or...? Confusing question, if you ask me. How would I go about determining the identities? Thanks.

So increasing cholesterol can contribute to the stoppage of heart rate? Does coffee contain cholesterol? Say if I drink 20 cups of coffee and run fast full speed, it will make my heart stop?

Why not? We live in a system of slavery and greed. It's hard to believe that it's actually hard to kill myself, we have strong survival instincts and such. We only exist so others can profit from us.

Maybe it has something to do with electrons or just charges aren't right.

So, I'm trying to draw a diagram for ionic bond, the question asks me to choose two atoms that could participate, and draw the valence shell I chose Mg and S. So, Mg has 12 protons and 12 electrons, and 2 valence electrons. S has 16 protons, 16 electrons and 6 valence electrons. In the diagram, I drew two atoms with 3 shells, and I will draw an arrow pointing the electron transferring to S shell from Mg's outer shell. How does that sound? Only one electron is transferred to S shell, is this correct? Or two? Because in Mg's outer shell there are 2 valence electrons... Thanks guys.

Or a counsellor. Oh, and nothing's gonna happen bro, relax!

Okay guys, I think you all nailed this thread pretty much. Thanks!

In my textbook, given example, it says: Write the name of the compound that has the formula Cu3N(s). 1. Identify the ions that form the compound Cu? copper ion, N3- nitride ion 2. Use the charge of the nitride ion (3-) and the rule that the total positive and negative charges in the formula unit must be equal. Three copper ions are present in the formula unit so each must have a charge of 1+. 3. Write the name of the compound. The name of the compound is copper (I) nitride. So, according to #2, I don't get the "rule", how would I determine this? How are three copper ions are present in the formula unit? Does it go something like this... N3-: 3 Cu+: 1+1+1=3 Therefore, ratio is 1 to 3 or 3 to 1....therefore copper (I) nitride? In the periodic table, Copper element has two charges, of 1+ and +2, so +2 is out of the question because it does not match up to 3 (equal to Nitrogen's charge), therefore +1 is applicable. Am I right? I fucking can't still figure out PbO2, originally I wrote lead (II) oxide, because I saw the number "2" and assumed it would have to be switched to left side. However, in textbook answers it says "lead (IV) oxide", why is this? What's the rule I have to follow? Can anyone explain to me please? Thanks....

How come we don't have walls anymore like those in medieval ages cities had? Imagine with all the technology today and knowledge, we probably could build the strongest one than ever before made...

So, Cu2S would be called Copper (I) Sulfide? Why would CuS be called Copper (II) Sulfide? Why? Would I have to figure out some ratio for both elements? Sorry, I'm trying not to be confused and am attemping to see a pattern here... Thanks for replies, gentlemen.

I'm trying to figure out the name for this formula, Cu(bottom 2)S, would it be called Copper (II) Sulfide or just Copper Sulfide? Seeing that Copper has two charges, 2+ and 1, and Sulfur has only 2-. Thanks!

It amazes me how bodies have to be run automatically, yet we're only able to control a few parts. (Eyes, limbs, etc...) What if we don't like our bodies or lives? Why must the nature make us deal with it? You make a good point though, neals. Thanks for your post.

I'm wondering, could anything have done to prevent this illness for this man? Please take a look at this article: http://www.dailymail...l#ixzz1mWtbta6c Thoughts? I can't believe that a pain like this can make you really commit suicide..poor guy.

I'm wondering if it's possible to make my heart, or for one's heart to stop from beating with will? Like I know we can blink our eyes, move arms, legs, etc. But what about heart? Would you need some kind of superpowers to be able to do that? Thoughts? I've been wondering this for a while.

I'm confused, "which groups would you expect to be more reactive than others and why?" Is it metals, or metalloids or non metals, or just noble gases? Or both metals and non-metals? Or alkaline metals and alkaline earth metals? My textbook doesn't really specify what makes less "stable".... Ok so those elements that do not have outer energy levels filled, are most reactive - am I right? Which group is that? Ok I got it so, I wrote, "Alkali metals are likely to be more reactive than others, because this group has less electrons in energy shells". THERE! Nailed it. (Hopefully) I fixed the first one, sir - "Atoms are the smallest part of an element that still has the properties of the element", as atoms do not combine to form compounds... Right thank you, neutrons are neutral as they are neither positive nor negative therefore no charge!

So we know that periodic table is 143 years old, and I wonder - Have we run out of elements that we have already discovered on this planet earth? What is the periodic table going to look like in 500 years from now on? Are the new elements going to be added to our periodic table when we visit other planets?

Thanks for the replies, guys. Here is the last question, What is the meaning of "reactivity"? Which groups would you expect to be more reactive than others and why? I wrote, "Reactivity" depends on the number of electrons required to get to the nearest complete energy level. As for the second question, how do I determine this? Thanks again.

Hi thanks for the reply; I am studying the periodic table at this point. So, Sulphur has 16 protons, and valence electrons is 16? Since sulphur is in group 16 then? Here's something I don't understand...why is this: How many valence electrons does magnesium have? - 2 How many in fluorine? Nitrogen? Carbon? - 7, 5, and 4 Why 2? Why 7 for fluorine and 5 for nitrogen and 4 for carbon? Can anyone please explain in simple words? How would I determine the number of valence electrons for sulfur, oxygen, hydrogen, aluminum, and magnesium? It's from my questions and answers notes I wrote from my class. Unless I wrote it wrong, fluorine should be in 17 since it's in group 17 and nitrogen should be 15 since it's in group 15 and carbon should have 14 valences since it's in group 14? I need the group name for Sulfur, clearly I can't determine this...

So, here's what I got so far... ------------------------------------------------------------------------------- True/False, if the statement is false, correct it. I wrote my answer in brackets... T - All matter is composed of atoms F - Electrons are positively charged, protons are negatively charged. (Electrons are negatively charged, protons are positively charged) T - Atoms combine to form compounds T - Most of the mass of the atom is in the nucleus F - All particles of the nucleus are charged (Only neutrons are negative) T - All halogens can become anions F - Magnesium has more energy levels than Aluminum (Opposite) T - Ba has 2 valence electrons F - The molar mass of copper is 58.93 g/mol (63.55 g/mol) ------------------------------------------------------------------------------- Write the formula for calculating mass number: mass # = # of neutrons + atomic # Complete the table (Element name, Mass Number, Number of Protons, Number of Neutrons) Chromium - 52, 24, 28 Magnesium - 24, 12, 12 Iron - 55, 26, 29 Calcium - 42, 20, 22 Chlorine - 35, 17, 18 ------------------------------------------------------------------------------- How did I do/doing so far? Thanks guys. I'm confused, how do I determine the group name for element Sulfur? And the number of valence electrons for it as well...

You guys make good points, but something really has to be done. Hopefully he steps down, if that's what people over there really want. It's too bad some (important?) people value power over the human life, it's depressing to know this but...you get the point. It's like the next classroom to ours is being loud enough that something has to be done for it to stop being loud...in order for our classroom to be in a peaceful state.

Why? Look at this jawless child...please be warned, videos are very graphic. http://i.imgur.com/pwpg7.jpg (WARNING: NOT FOR THE FAINTHEARTED, VERY DISTURBING IMAGE. DO NOT CLICK IF YOU'RE UNDER 18) http://www.youtube.c...pcontrinter%3D1 U.N. or U.S. or Russia should invade Syria to remove its corrupt government or something, am I wrong? Apparently, Syrian government is OK with this. Apparently, government soldiers / officials are OK with this. Apparently, world is OK with this. Apparently, governments across the globe are OK with this. Disgusting....can't believe what I found or discovered. I seriously feel bad for this guy. Assad or whatever his name is, is obviously an evil dictator.