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Chemistry: Ions and Ionic Compounds help?

Chemistry: Ions and Ionic Compounds help? Topic: How to write a ionic compound formula
May 26, 2019 / By Genia
Question: So basically I have a chemistry test tomorrow and this is going to be on it. SO I understand how to write the proper notation for an Ion (e.g. S = S-2) and so on. But then we get to this part where when you combine two ions together my mind goes wack and can't understand it. If you dont know what I'm talking about there's one example where "F-" and "Na" are combined to get "NaF" but I remember my teacher saying stuff about borrowing electrons and adding more ions to make it even but it's all extremely confusing to me. If you could help that'd be awesome. But keep in mind I'm only a sophomore in high school so try to keep it somewhat simple. Thanks!
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Best Answers: Chemistry: Ions and Ionic Compounds help?

Del Del | 10 days ago
i know what your on about. Iv just been revising this for A level. OK basically in ionic compounds the formula is made due to atom charges. You'll understand what im on about in a minute. In ionic compounds atoms either lose or gain electrons. Its very important to know an atoms charge and to know its charge you need to look at the periodic table. i gave a link to a periodic table. If you look at the periodic table i gave the link to it says 1A 2A 3A 4A 5A 6A 7A 8A this is what you need to know the charge of an atom. 1A means it has 1 extra electron. 2A means the elements under 2A have 2 extra electrons 3A means the elements under 3A have 3 extra electrons. 4A means the elements under 4A have 4 extra electrons. And so on up until 7A. 8A doesn't need to lose or gain any electrons because it already has 8 in its last outer shell. group 1A have 1 extra electron in their outer most shell and they need to get rid of it in order to become stable. So for example lets look at Na (sodium) Sodium will have a charge of +1 because it need to get rid of 1 electron in order to become stable. Lets look at Group 7A now and lets use bromine. bromine has 7 extra electrons in its outer shell. And remember if it reaches 8 electrons it becomes stable so if Sodium gives the extra electron it has to Bromine which needs 1 more electron to become stable. And the charges are used to write out the symbol formula. Na has a plus 1 charge and Bromine has a negative 7 charge. Na+1 Br-7 To write down a symbol you simplaly bring the charges from the top to the bottom and cross them over so the charge of Na which is +1 goes to Br and the -7 charge from Br goes to Na. So the formula would now read, Na7Br Remember that you have to remove the charges after you've bought the numbers down from the top to the bottom. So Na7Br tells us that there are 7 Na atoms and 1 Br atom. Another example. Magnesium Mg which has a charge of +2 because its in the 2A column. and oxygen Which has a charge of 2- because non metals always gain electrons and electrons are negatively charged so if it gains 2 more electrons its gonna become more negative that's why its 2- If you cross over the charges Mg+2 O-2 <----------------- cross the charges over and put them at the bottom and it becomes Mg-2 O+2 <--------------- Remove the charges and it becomes Mg2 O2 You can simplify this because 2 cancels out 2 so the final answer would be ---------------> MgO Hope this helped good luck :) If you have any further questions just add me on [email protected] and ill be more than happy to explain to you there properly and in more detail.
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We found more questions related to the topic: How to write a ionic compound formula


Del Originally Answered: Ionic compounds?
d. i is true. ii. is saying the opposite of i. covalent bonds are formed when atoms share valence electrons so it is false because ions don't form covalent bonds. iii. is true as long as it is not in aqueous solution. iv. this is false, especially if they are in ice water. do your own chem homework nextime.
Del Originally Answered: Ionic compounds?
III only i an ion such as CO3--contains covalent bounds -false ii this is a covalent bound -false iii correct Iv false

Brooke Brooke
It all has to do with filling the valence shell ("octet"). Chemicals and compounds all want to fill this octet because they become lower in energy and thus "happy." So let's take your NaF example. Fluorine (F) is in the 7A column (F, Cl, Br, I...) which means it has 7 electrons in its outermost shell. So in order to get 8 and be happy (as all compounds usually want to be), it must get another electron from another ion. Sodium (Na) is in the 1A column, and thus has only one electron in its outer valence shell. So when Na and F get together, fluorine can essentially use sodium's valence electron, giving it 8 valence (outermost) electrons, which makes it "happy" and stable.
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Brooke Originally Answered: How do you make ionic compounds?
Think back, how do you make a sulphate? Answer: from sulphuric acid, reacting with a metal. ("Performed well" is obviously a relative term here) :) Of course, you need the pure metal and the sulphuric acid (often sold as drain cleaner, but if you get concentrated sodium hydroxide it's a whole new world of pain. Read the label) As far as I remember, for a cell, you don't usually use ionic compounds as electrolytes unless you are electrolysing them. Most cells have acids or alkalis in them. You need to read more about making cells. A simple cell of copper and zinc will give you around a volt, but the zinc will react with an acid electrolyte, so you may not want to use it. Silver and copper will give a nice cell, though the copper will corrode. Carbon and zinc will give 1.5 volts, but it polarises easily, which is why AA cells and similar have all that black gunge in them. Lead-acid accumulators are easy enough if you can get the acid, but it needs to be about 4M concentration (potentially dangerous) to work well and an acid-proof container is essential. The web is full of information about cells, it's just interpreting it that's the problem.

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