Chemistry in tiny, tiny bites: Ionic Bonds.

Does chemistry bring you out in a cold sweat? Then I hope these small bitesize chemistry bits will help. Today I’m covering ionic bonds.

I have written this blog for a friend of mines daughter- who is crazily bright- but hates chemistry with a passion and JUST. DOESN’T. GET .IT.

Here goes…you know who you are.

Opals- a hydrated form of silica
Opals

It starts with matter. Everything around us. And what is crazy is that by changing the atomic structure of the matter that surrounds us we can change its physical properties.

Matter is; wool and metal and sugars and fats and basically everything. These “things” are made from building blocks, that in their simplest, purest forms are elements.

How else would a cow that eats only grass produce milk that we drink? (Clue:Change chemistry of the grass to convert it into fat and sugar)

One form in which we find pure elements or simple combinations of elements in the earth are minerals and crystals. These help us understand what and how the earth is made up. Crystals themselves have these amazing flat planes that reflect light and this is due to a highly ordered internal arrangement of atoms.

Crytals and chemical bonding
Sulphur crystals-

What makes some crystals hard, or very twinkly, or crumbly, is the way their atoms are arranged in a uniform manner and how they are bonded, namely: metallic, molecular, covalent and ionic.

Crystals therefore become an easy way of describing chemical bonding.

Aquamarine
An aquamarine the size of your fist- an example of covalent bonds

Diverse crystals are made up using different types of bonding of their atoms which gives them different properties for example : Diamonds: made from covalent bonds: [covalent (where atoms share electrons and are very hard to break (BFFs) and hard as ..diamond)].

diamonds -covalent bonds
Every colour diamond on the planet- some glow .

Ionic bonds in crystals

An ionic crystal is also known as a salt. (Little crystals of table salt for example.) 90% of all minerals we find in the earth are ionic compounds. So to describe ionic bonding we can use a goto example: Table salt.

Ionic solids (think of salt), unlike covalent solids (think diamond) -crumbles easily, is soluble in water and conducts electricity- figure out why if you can.

Ionic solids aka crystals aka salt (take your pick)- are made from a highly ordered and repeating lattice structure, but the geometry of the lattice depends entirely on what types of ions (elements with a charge) you have and their ratio.

Ionic compounds form different shapes because the way atoms intersperse with each other isn’t just random. Smaller atoms fit into spaces between bigger atoms, attractive forces influence everything and so ionic bonds make lattices that can be different shapes; tetrahedral, octahedral etc .

Ionic bonds as salty salt crystals

There are many types of salt- but we’re going for the table salt you put on your chips. And that is made from 2 elements Sodium (Na) and Chlorine(Cl).

Sodium (Na) by itself it’s a crazy little metal, you stick it in water and it fizzes like a bath bomb, but combine it with…..oh, I dunno chlorine (Cl)- which is also quite a toxic gas and………poof!

Voila: you have sodium chloride (NaCl)- or table salt, ( Halite crystal ).

Na+(sodium ions), are essential in nervous conduction for example- and yet we don’t explode. Combine Sodium with a hydroxide and you get Sodium hydroxide- or NaOH, commonly known as caustic soda. Great for dissolving pretty much anything (Good for drains).

Get your head round the fact that chemicals aren’t bad things they are just the things that are around us.

Well the premise for all of this toing and froing with sodium is that in nature it exists a lot in its ionic form (like NaCl). And these rules can apply to ALL elements. I’m just using sodium as an example.

What is an ionic bond?

Let’s see if you know these facts. If you do- we can move on. If not- learn them.

All elements exist with a central proton and neutron and a shell of electrons

If you know this then continue……

Electrons carry negative charge

If you know this then continue……

This shell of electrons changes with each element and there’s a pattern to it

If you know this then continue……

As the element gets bigger, the number of electrons increases and matches the size of the protons- so big atomic mass=loads of electrons.

If you know this then continue……

The electrons come in layers- like the circles of hell. They sometimes follow a trend, (unless you’re a crazy metal), but it’s the ones on the outside that can have the biggest influence

If you know this then continue……

If you can’t remember or work out how many electrons are in the outer shell, then look to the placement of the element in the periodic table. Group 1 has, yes you’ve guessed it, 1 electron in its outer shell.

Now here we go…..

Atoms have electrons in their outer shells- in this example either 1 (a group 1 metal) or 7 (a group 7 element)
Odd electron numbers mean that you are not as stable as you could be.

More electrons means more negative charge and more attraction.

With respect to your outer shell, if you have very few electrons in your outer shell, you are not very attractive, sort of weak. What you ‘want’ is to fill your ‘shell’ of electrons. Normally you can hold 8 electrons in your outer shell, so in order for the element (that only has 1 electron) to find peace, you either lose an electron or gain another 7. (It’s easier to loose 1 than gain 7).

So far so good?

Now, like I said, sodium is a group 1 metal. What about chlorine?

If you sneak a peak at the periodic table you would see that it belongs in group 7. What this means is that it has seven electrons in it’s outer shell. And what this means is that for it to be stable it will require 1 electron from somewhere. So, technically, any element that has one electron kicking about in its outer shell would seem an appealing thing.

They don’t want to share though. nuh uh.

Picture the scene, sodium and chlorine approach, they are attracted to one another and all of a sudden, whoop, the electron from Na is suddenly ‘donated’ to Chlorine. Its a win-win situation. Chlorine now has its shell filled and Na has lost the electron. Because of this loss of negativity, Na becomes Na+, that’s how you can tell its ionic (has charge). Cl becomes Cl-.

electrons ions ionic bonding
Donation of electrons from an atom with one electron in its outer shell

The charged ions stick around each other as opposites attract. There will be problems however if other more attractive ions turn up- but for now if it’s just them, they remain in this relationship.

Learn this: + ions or cations tend to be metals. – Ions or anions tend to be non-metals.

A salt (such as table salt (NaCl), has a balanced number of ions, 1 Cl- to 1Na+. Therefore overall there is NO CHARGE on the element

ionic bonds
Elements from group 1 and 7

When it crystallises, it becomes what we put on our chips.

This is an ionic bond- related topics: Acids and bases, titrations, crystals the world.

Youtube video for one of the most ‘fun’ ways of explaining chemistry https://www.youtube.com/watch?v=QXT4OVM4vXI

Interestingly- each mineral and ion we find in the group has its own colour

colours of crystals- like emerald and sapphires is dictated by the types of ions it has in it

The chemistry of colour and why colour is what it is, is for another time…….

I hope you found this helpful- please follow me if you want more updates….




Revision tips to get you started.

It’s getting close to that time of year again, the sun is out but you’ve got to be inside studying , because it’s exam time and revision is on your mind.

Thinking of somewhere else you’d rather be?
Photo by Pixabay on Pexels.com


I feel for you, I really do. We’ve all been there. We all hated it. Anyone who tells you that revision was no problem for them or who weren’t revising were fibbing.


Through a process of many years of sitting exams, then setting exams, chatting with students and having children now going through the exam process, I’d like to think I have a few insights into the exam process.

Once you get over the fact that exams are inevitable, or if you choose a certain career or other, you may find that exams are part of your life. If you accept that you just have to get on with it, grit your teeth and deal with it and get down to revision, you’ve already won half of the psychological battle. This applies to every exam from school to university and beyond.

So where to begin.

It’s very simple. Begin.

No matter how daunting, no matter how great the task ahead of you, if you don’t start, you won’t finish.

Most of this anxiety comes from a total lack of confidence and what you must do is have a belief in yourself.

Now, I’m not saying don’t revise, don’t work and walk into an exam thinking it’s all going to be great, because it won’t. However, if you know you have to undergo some sort of test- accept it, it’s easier than battling with an attitude of not wanting to do it, or of thinking how unfair life is. Woe is me.

 Now you’ve accepted it, prepare. You wouldn’t run a marathon without training, would you?

So, here are a few of my handy revision tips that I hope provide some logistical way forwards for you.

Make revision notes

You may think this is a little old school, but then again, the exam system is. Notes, I find, are your go to. Notes as I call them, are the thing where you put all of your ideas, explanations about a topic that have enabled you to understand them, practice papers, and directions as to where your ideas came from. Ultimately, the day before an exam you just go to your notes and they should look after you.

Learn stuff.

I’m sorry- sleeping with your notes under your pillow does not work. You do not learn by osmosis. Revision is hard work- not because its hard, but because it’s making you do something when you’d really rather be doing something else.

Make yourself learn stuff. Find out your strengths in learning and play to those strengths . Are you a visual learner? If so, draw pictures of what you need to learn and stick them everywhere. Are you a person who needs to hear things? Then record your thoughts, most phones have dictaphones, record what you need and listen to it. You get the idea. Revision is not a one size fits all.

When you are learning, some people have suggested that memory pathways can also be created by smelling certain smells. Get some oils – peppermint, rose, lavender, whatever- and have it close by when revising a certain subject. On the day of the exam, whip out a handkerchief with the smell on- it should trigger those memories associated with whatever you were revising at the time.

Immersion and consistency.

If you’re trying to revise for maths and any other sciences it’s really difficult to revise at the last minute, particularly for maths. Maths, like chemistry I have found, can be drip fed over a period of time, and then for some reason the penny suddenly drops and you just get it. For maths, doing all these tests online is okay, but your exam is going to be on paper, so go old school and do your maths revision on paper. Every day 15 minutes at least. The familiarity makes it easier to walk into an exam.

The same as I have mentioned, is true for the sciences. Familiarity with scientific language, scientific approach and articulating ideas comes from consistent exposure to these subjects. If you happen to be one of those people who somehow switched off during class (yes we’ve all been there), then during revision time when you’re learning everything, consistent small doses is what you need.

Use one or two good websites as resources for revision

There are numerous amazing sites with information to help you revise and pass your exams. This doesn’t mean that your teacher isn’t good or that you aren’t a good student. We all learn in a particular way and if you have missed a lesson or two or are not on the same wavelength as your teacher, that’s okay but it can become a problem if you disengage and don’t try and get help to see the problem from another point of view.

For those doing GCSEs, I do recommend the BBC bite-size courses https://www.bbc.com/bitesize , they allow you to get the bare bones of the subject down and provide tests of every subject to see if you’re following. As with every test, if you’re not getting 100% in these online things keep repeating them until you do.

I’m aware that exam criteria will be different across the globe but these examples are aimed at those who are doing exams at about age 16. It may not be specifically targeted for what you want, but by doing other courses in the same field you end up gaining a breath of knowledge. Remember, no work is ever wasted.

Practise under exam conditions

Finally, I would say that after you have revised as much as you can revise, after you have practised as much as you can practice with little test questions, you actually set a practice exam and exam conditions. Pretend you are sitting in exam. Give yourself two hours, get your clear pencil case and all your stuff in it, then off you go.

Get nervous when sitting the practise ‘exam’. This will be on your terms. As I have said in previous blogs https://franscienceart.com/2019/03/27/6-simple-and-effective-exam-revision-secrets/, inducing control over your anxiety by being in a familiar setting, you can work towards preventing anxiety in the real exam, and in doing that you can enable yourself to be on top form.

I know exams are difficult and I hate them. I think it’s because we know that they are a mechanism of being judged. Just remember what’s important to you when you’re sitting these exams. Why you’re doing these exams is irrelevant. These exams are reflection of everything that’s going on in your life right now and if you nail them and do very well, well hats off to you, but honestly, to me, what I respect the most is that you tried and I don’t just mean, like, when your mum says ‘ well at least you tried’.

You faced your fears, and you did it anyway. Even though something can be so tough, you’re brave enough to face it and you may find you get you don’t get what you want, but people I respect are those who:

  • Prepare
  • Get ready
  • See what happens, come what may.

If you can do that and you have given yourself a life skill that is invaluable.

Bring it on.