salters’ salty science · 1 salters’ salty science salters’ salty science salt contains two...

SALTERS’ SALTY SCIENCEENCOURAGING TOMORROW’S CHEMISTS TODAY

HOME ACTIVITY PACKSUITABLE FOR AGES 9 — 13

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1 SALTERS’ SALTY SCIENCE

SALTERS’ SALTY SCIENCE

Salt contains two elements, Sodium (Na) and Chlorine (Cl)

and its chemical formula is NaCl.

Salt has played an important role in people’s everyday lives for

thousands of years! The availability of salt allowed civilisations to

preserve food in a time when there was no electricity and

consequently no fridges or freezers.

- Salt draws moisture out of meat, fish etc.

However, salt was difficult to obtain and a highly valued trade item.

Salt was so important and valuable (sometimes even more than gold)

that in Roman times people were paid their wages in salt, hence the

word ‘salary’. ‘Sal’ is Latin for salt.

Today there are three main methods for producing salt:

- evaporation from sea water

- mining salt from the earth — through cutting, drilling and blasting

- creating salt brines — pumping water into rock, the salt dissolves

and comes to the surface as brine.

Nowadays, the majority of salt produced is used in the

chemical industry to produce other useful materials that

are essential to modern life.

Sodium Chloride (NaCl) is used in the following:

- medicines

- soaps

- de-icing pavements and roads

- the manufacture of plastics.

SALT FUN FACT!

Did you know that salt has been so important to civilisation that in Britain the suffix ‘-wich’ in a place name often indicates it was near a source of salt?

e.g. Middlewich, Northwich, can you think of any other towns with the ending ‘-wich’? Why not look up their history?

saltersinstitute.co.uk @salters_instENCOURAGING TOMORROW’S CHEMISTS TODAY

https://www.saltersinstitute.co.uk/

https://twitter.com/salters_inst?lang=en

2 SALTERS’ SALTY SCIENCE

As trading in salt became more important, in large cities and near

ports where much salt was imported, ‘Salters’ began to group together

to look after their trade and interests.

The Salters’ Company received its first Royal Licence from King Richard II,

in 1394 to be able to trade in salt.

In 1515, the Order of Precedence was set for the 48 Livery Companies

then in existence. The Salters’ Company was ranked at number nine in

the Great 12 for its economic power.

THE SALTERS’ COMPANY

THE SALTERS’ INSTITUTE

salters.co.uk

The Salters’ Institute, the Salters’ Company’s

flagship charity was founded in 1918 to support

the UK chemical industry by helping returning

servicemen to study chemistry.

Nowadays, the Institute aims to promote chemistry

and related sciences amongst the young, and to

encourage careers in the teaching of chemistry

and in the UK chemical and related industries.

saltersinstitute.co.uk

Encouraging Tomorrow’s Chemists Today!


https://www.salters.co.uk/




3 SALTERS’ SALTY SCIENCE | CREATIVE CRYSTALS CHALLENGE


Particle Theory

Everything on earth is made of particles and are in one of three states of matter:

SOLID

In a solid, the particles:

- Are close together

- In a regular arrangement

- Vibrate on the spot

CREATIVE CRYSTALS CHALLENGEIn this challenge you will be growing your very own crystals at home, as well as seeing just how creative your photography skills can be!

But before we begin, let’s talk about crystals…

LIQUID

In a liquid, the particles:

- Are close together

- Randomly arranged

- Move around each other

GAS

In a gas, the particles:

- Are far apart

- Randomly arranged

- Move quickly in all directions

ACTIVITY 1





What is a crystal?

A crystalline solid is made up of particles which are arranged in

an ordered grid-like structure often referred to as a lattice. Crystals

are found in all kinds of everyday materials and their shape and size

heavily influences their properties. For instance, the smoothness of

ice cream and the absorption of aspirin by the body are each

dependent on crystal size and shape.

DIAMONDS

RUBIES

Can you think

of any crystals

that exist around

you in everyday

life?

How are crystals formed?

The process when crystals form is called crystallisation.

Crystals form in nature when liquid rock (called magma)

cools and starts to harden. As the liquid cools, certain

particles in the liquid gather together into a uniform,

repeating pattern, to form a crystal.

This process is how rubies, diamonds and

emeralds are formed!

Another way crystals can form is by evaporation.

For crystals to form this way you need to make a

saturated solution.

A saturated solution is a solution at the limit of solubility

— where no more solid can dissolve in it. When the liquid

in the saturated solution begins to evaporate, the solution

becomes supersaturated. A supersaturated solution holds

more solid than its limit.

Evaporation is the method you are going to use today

to grow your own salt crystals.

ACTIVITY 1

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Table salt is made of many tiny crystals. Different crystals have

different properties and shapes. For example, sugar crystals are

oblong and slanted at the ends; salt (NaCl) crystals are cubic.

Now you are going to grow your own salt crystals

Have a go following the method on the next page first. After

following this method, have another go, but this time try changing

some of the factors to see how your outcome is different. You

can use the ideas on page 7 as inspiration for what you could

do differently.

SALT(ERS’) CRYSTALS

You will need:

- A jug or medium sized bowl

- A clean glass jar, e.g. jam jar

- 200 ml of hot water

from a hot tap

- 150 g table salt

- A teaspoon

- String

- Sellotape

- Scissors

- Paperclip

- Pencil

Safety checked but not trialled by CLEAPSS

SUGAR

SALT

SAFETY!

- Do not consume the materials or liquids used in this experiment.

- Depending on how much food colouring is used, some temporary

staining of fingers may occur.

- Wash your hands after the practical.

!

Optional

- Food colouring

- Pipe cleaner

Remember to write

down your method

as you go along.

We want to know

how you created

your unique

crystals!

ACTIVITY 1

EASY Grow your own crystals and challenge your creativity!

2 — 3 DAYSAGES 9 — 13

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ACTIVITY 1

Pour 200 ml of hot water into a jug.

Add 50 g of salt and stir until the water is completely clear.

Add a teaspoon of salt into the solution and stir. Repeat until the salt will no longer dissolve.

Leave the solution to sit for 2 minutes.

Very slowly pour the solution into your jar, make sure you stop pouring before the salt grains pour into the jar.

Use a pencil and a piece of string to suspend your paperclip in your salty solution.

Move the jar to a safe place where it will be undisturbed.

TOP TIPS

1 tablespoon is approx. 25 g

If the salt will no longer dissolve and sits at the bottom of your bowl after stirring for a while, your solution has become saturated. You may not need all of the salt.

Make sure your paperclip isn’t touching the bottom of your jar.

If the pencil doesn’t stay still, tape it to the top of the jar.

How much do your crystals grow each day? Could you take a photograph every day and produce a timeline?

Now you have to be patient as your crystals will take a little while to form! Check on your crystals every two to three days and you will eventually see little crystals growing on the string, they will usually get bigger over time so check your crystals regularly!

FINISHED?

- Time to dispose of your solution and crystals carefully.

- Remove the crystals and any extra salt from the solution

and place in a bin bag into non-recycling waste.

- Pour your solution down the drain with plenty of water.

!HAVE

ANOTHER GO!

Use the tips on the

next page to change

some of the factors

to see how your

outcome is

different

200ml

100ml

400ml

200ml

100ml

400ml

200ml

100ml

400ml

100ml

200ml

100ml

400ml

SALT

200m

l100m

l

400m

l

1

4 5

6 7

2 3

2 mins

ACTIVITY 1

Method





SALT(ERS’) CRYSTALS

ONE STEP FURTHER…

Try adding some food colouring to your solution and see what happens!

What happens if you use a pipe cleaner and not a paperclip? If you bend the pipe cleaner into a shape will the crystals grow around it?

What happens if you use cold water instead of hot?

Will the crystals look different if you use a different type of salt? (e.g Epsom salt)

What happens if the jar is left outdoors in the sun? Or in the fridge?

EPSOM

SALT

1 2

3

4 5

Try changing some factors to see how the result is different!

For example, you could experiment with:

Try and figure out what works the best.

ACTIVITY 1

200ml

100ml

400ml



ACTIVITY 1ACTIVITY 1



The salty solution in your jar is called a saturated solution because you have

dissolved as much salt as you can into the water.

Over time, water will evaporate from the surface. This means the concentration

of the salt in the solution will increase making it a supersaturated solution.

Supersaturation is an unstable state. In order to get back to a stable saturated

state, the solution will deposit the excess salt onto a ‘crystallisation nucleation’

site (which in this case is the paperclip and string) and a salt crystals starts to form.

At the same time, more water evaporates and the growing process continues as

the solution continues to deposit excess salt to reach saturation.

The combination of evaporation and deposition (the laying down of material)

keeps the crystals growing.

THE SCIENCE

We would love to see fun photographs of your salt crystals

along with a description of the method you used to get there!

Even better, why not try taking a photograph of your crystal every

day and make a time-lapse of it growing. So put your creative hats

on and get snapping! We are looking for interesting photographs

of your crystals, so remember, the best photograph is not

necessarily going to be the best crystal.

We will be awarding prizes and certificates for the best entries.

Now that you have waited patiently for your salt crystals to grow, your challenge is to take a really creative picture of the finished product.

If you do not have Twitter not to worry

just email your entry to us at [email protected]

Tag us on Twitter

@salters_inst | #salterssaltyscience

TO ENTER

TOP TIP

Make use of different lighting, backgrounds and props — the more creative the better!

All entries must be submitted before

FRIDAY 4TH SEPTEMBER 2020 — GOOD LUCK!

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ACTIVITY 2

9 SALTERS’ SALTY SCIENCE | FISHING FOR ICE


Forget fish, let’s try fishing for ice

Can you lift an ice cube out of a glass of water using

just a piece of string?

It might sound impossible, but in this simple experiment,

we’ll use the powers of salt to show you how it’s done.

You will need:

- 4 or 5 ice cubes

- 12 cm piece of string

- A medium-sized glass

- Table salt (NaCl)

- Cold water (H20)

FISHING FOR ICE

Safety checked but not trialled by CLEAPSS

MEDIUM Learn how salt influences temperature and be creative to share the process!

20 MINSAGES 9 — 13

SAFETY!

- Do not consume the materials or

liquids used in this experiment.

- Wash your hands after the practical.

!

Can you get an ice cube out of the glass using just a piece of string? Have a go!

Impossible, right?



ACTIVITY 2



Place the ice cubes into the glass

Fill the glass halfway with cold water

Lay the piece of string over the ice cubes

Sprinkle a pinch of salt over the string where it touches the ice cubes

Wait for 45 secondsNow gently lift the string up!

FINISHED?

Place your string in non-recycling waste and wash out

all the equipment you used.

!

TOP TIPS

Oblong and square shaped ice cubes work best!

You will have much better luck if you wet the string first.

HAVE ANOTHER GO!

Use the tips on the

next page to change

some of the factors

to see how your

outcome is

different

SALT

1

4

5 6

2

3

TA DAH!

The ice is

lifted out of

the water

45 secs

Method



ACTIVITY 2



Replacing the salt with sugar, sand, flour, you name it! Do they work as well as salt?

The amount of salt you add

The length of time you wait before you lift the string

FISHING FOR ICE

ONE STEP FURTHER…

Challenge other people to pull ice out of a glass using only a piece of string and then show them how it’s done!

SALT

1 2 ?

Try changing some factors to see how the result is different!

Can you think of any factors which might affect how well the

ice sticks to the string? For example, you could experiment with:

Try and figure out what works the best.

3

Try attaching your

piece of string to

a wooden stick

to make a proper

fishing rod!



ACTIVITY 2



The freezing temperature of water is

0 degrees Celsius (°C)

Can you figure out how you managed

to lift the ice cubes on the string after

you added salt?

Your challenge is to explain how this experiment works in the

most creative way you can! It could be an illustration, a story, or

even a stop-motion video. The more creative the better! We’d

love to see your answers and will be awarding prizes

and certificates for the best entries, so get creative!

So, it is possible to fish for ice using just a piece of string, but only if you add a pinch of salt — how strange!

THE SCIENCE

If you do not have Twitter not to worry

just email your entry to us at

[email protected]

Tag us on Twitter

@salters_inst

#salterssaltyscience

FUN FACTS

Freshwater will freeze at 0 °C, but seawater freezes at -2 °C. Why? Because seawater is salty!

Salt is spread onto icy roads in the winter to make the ice melt and keep the roads safe!

TO ENTER

Salt lowers the

freezing temperature

of water. Therefore,

the ice will start

to melt where it

touches the salt.

All entries must be submitted before

FRIDAY 4TH SEPTEMBER 2020 — GOOD LUCK!

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SALTERS’ SALTY SCIENCEENCOURAGING TOMORROW’S CHEMISTS TODAY

Salters’ InstituteSalters’ Hall

4 London Wall Place

London, EC2Y 5DE

020 7628 5962 | [email protected]

saltersinstitute.co.uk

@salters_inst



salters’ salty science · 1 salters’ salty science salters’ salty science salt contains two...

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