Answered by Alex Nicholls

Rice Krispies are made of crisped rice (rice and a sugar paste that is formed into rice shapes or "berries", cooked, dried and toasted), which expand forming very thin and hollowed out walls that are crunchy and crisp. All the tiny air bubbles trapped inside the Rice Krispies begin bursting when one adds the milk, and the small variations in air bubble sizes causes slightly different noises, making all the snap crackle n pop sounds one hears. 

Nice as that sounds, (apart from the excess sugar) the reason for the noises could be is a little less friendly. It could be due to the high salt content in Rice Krispies because one gets the same reaction when one adds cold water to salt.

Well done Alexandra! What a fantastic question! We chose this as a winning question because it seems a simple question but covers so many different areas of science. It is also an area of science a lot of children are confused by - what gases are like, how we see them, what they are. So we thought lots of other children would enjoy reading the answer as well (and probably lots of adults too - they often pretend to know but probably they need an answer as much as you!) Congratulations on winning a copy of Brad's 'Do Try this at Home' book and a certificate. We met you at Isla and Lola's Gross Party in Brighton so will find a way of delivering your prize to you! Do feel free to reply to the answer as well after you have read it. We would love to know what you think. Lydia from Blast Science. Stay curious!

Your question has been answered by Sarah Newnham who is a young female scientist and a Doctor of Microbiology. She works mainly with bacteria and spends a lot of time looking down a microscope!

This question involves explanation of a number of different things. So I have separated this into a number of little questions...

Why do we see things?
We don’t actually see things, as such, we see the light . This can be the light they produce (sun, stars, light bulbs), the light reflected off of the object (you and me, the moon, cinema screens, books) or the light is changed when passing through it (water, glass). This is why you cannot see well at night, when there is only a little light, or nothing at all when it is pitch black but can see well in the day when there is a lot of light.

What is light?
Light is energy. We use the term to refer to the visible light we can see but light is a physics term that can be applied to all electromagnetic radiation. Electromagnetic radiation travels in wavelengths, of varying electric and magnetic fields. These wavelengths go in straight lines, their direction can be changed by contact with molecules, like visible light being reflected that we can then see. The spectrum of electromagnetic radiation includes; gamma rays, X-rays, ultraviolet (which can be seen by other animals, e.g. Bees, and can cause glowing/ fluorescing), VISIBLE LIGHT (including all the colours of the rainbow violet to red) infrared (which can be seen as heat with special glasses), microwaves and radiowaves (in order of shortest to longest wavelengths).

How can we feel air, in the wind, if we don’t see it?
Air is made up of a mixture of molecules and there is approximately 26,700,000,000,000,000,000,000 molecules in one litre of air. When we move through the air or the air moves around us, as wind, we can feel it as all the molecules collide with us. Wind occurs due to changes in pressure and these differences are what we feel as wind.

When can we see air or wind?
Air is ultimately transparent. This is because light can travel through the air without being affected this is because molecules are spread out , the molecules in solid objects are touching each other so there is no path through for the light, so it is changed and we can see it.

Here are some times when the air does change the path of light and we can see it:

- Tornado: Some of what you see is debris and dirt that is picks up but also you are seeing the formation of water (liquid) from the water vapour (gas) as the temperature and pressure drops fast inside the funnel of air.

- Blue sky: over the distance of the atmosphere molecules do affect the light from the sun. This is called light scattering. During the day when there is a lot of light from the sun more blue light is scattered than red light, from space the atmosphere also gives off a blue glow. However, at sunset we see red/orange colours as the blue light has been scattered further away and out of our line of sight.

- Mirage: Looking along a road (over a long distance) on a hot day wavy lines, that look a bit like water, can be seen just above the road. These are caused by the hot air rising and the bending of the light as it passes from colder to hotter air, this bending can also occur in the change between matter (for example a straw in water looks bent as it enters the water).

- Stars twinkling: The atmosphere has changing air pressures, low pressure has a lower density then high pressure and therefore reflects less light (or has a lower refractive index) as there are less molecules to alter the lights path. These changes in atmospheric pressure altering the light path cause stars to twinkle, the star is still producing the same amount of light we are seeing the change in air.

Answered by Brad Gross, Lydia Samuel, Mo Gibson & Alex Nicholls

From Lydia... Matthew what a fantastic question! We decided to award your question with a prize as we all felt it was such a thought-provoking, challenging and exciting question, which can be answered in so many different ways. Well done for coming up with a Science question that challenges even the scientists!

Why did we invent Science? The challenge is in unravelling the question. Do we mean are we interested in the world around us, as every human being has always been since people became conscious and aware of their surroundings? Or do we mean why did we invent the scientific method, in which you pose a question or hypothesis and then set out to prove whether you or it are correct using clear scientific methods. Either way Science is about understanding and making sense of the world around you and that is a very human need - to be curious and try and learn about how things work, to try and make sense of what is around you. Scientists are like curious toddlers trying things out over and over again to see how something works and learning about the world around them. Remember - we are all scientists if science is about curiosity and learning!

Here are a few possible answers. There will be many others. If other people have other ideas please post your comment after this post!

From Brad... Why science? Well that's a chicken/egg type question in my opinion. I don't think people invented science. I think people, eager to learn more about the world we live in, started to question, speculate and eventually experiment with the world around them. Like children, people are inquisitive. We want to know more. 

A lot of the science about the wonders of the natural and physical world is only just being unravelled. Not long ago people thought the world was flat. We now know that it is not. Science is about being dissatisfied with what we know. ...which suits humans perfectly. For better or for worse. 

From Alex... 


Caveman looked down and thought "Why is the grass growing?"
Neanderthal looked up and thought "Why does the sun rise?"
Copernicus thought "Is the Earth really the centre of all?"

So, is the question "Why did we invent Science?" or has it been here all the while and the question should really be "We try to understand how things work. What shall we call it?"

Congratulations on winning a signed copy of the 'Do Try this at Home' Science book featuring Brad! We will post it to your school, along with a certificate. Stay curious and keep asking questions!

Answered by Dr Sarah Newnham (Microbiologist)

To answer this question lets start with a bit of revision about the states of matter and its
properties.(distinguishing features or differences). Matter is defined as anything that has a mass and
takes up space. It is all around us and is all the things you can touch and see. The three main states.....

Solids
Tightly packed together/Regular pattern, held together by forces called bonds/Cannot move but can vibrate in place/Maintains shape and space

Liquids
Close together/Random arrangement, form weak bonds (keep together but can move)/Can move around each
other/Changes shape to the shape of the container but takes up the same amount of space

Gases
Far apart/Random arrangement, no bonds (do not stay together)/Move quickly in all directions/Changes shape and fills the space, also under pressure can be compressed into smaller spaces

There are other states of matter that are only seen in extreme conditions, for example plasma, which occurs at very high temperatures e.g. In stars. This is where atoms lose their electrons and the mixture of electrons and
atom nuclei form the plasma state.

So in answer to the question of why the molecules are arranged and act differently (have different properties) in different states is basically ENERGY.!!!

Matter can physically change from one state to another but the substance remains the same. These changes happen as the motion of the atoms are changed by the increase or decrease in energy. These changes can be caused by temperature and pressure, for

- temperature: water freezes to ice under cold temperatures (energy decrease) and when heated to boiling point (energy increased) it becomes steam, which is a gas

- pressure: deep inside the earth solids are changed to liquid, in this case magma, due to the pressure caused by the weight of the layers of the earth pushing down (adding energy).

All below answered by Dr Sarah Newnham (Microbiologist)

What is an Atom?
Atoms are the building blocks of ALL matter. Matter makes up the whole universe (excluding energy). Everything you or I can touch are formed from atoms including our bodies and the air we breath.

These atoms are formed of 3 particles called protons,neutrons and electrons. The protons and neutrons cluster together in the center, forming the nucleus, and the electrons fly around ‘orbiting’ the nucleus, called an “electron cloud”. The particles in the nucleus are responsible for an atoms weight, or mass, as the electron has such a small mass that it is said not to have any at all.

Atoms are held together by positive and negative charges, like a magnet. The protons, in the nucleus, have a positive charge and the orbiting electrons have a negative charge. This means the negative electrons are attracted to the positively charged nucleus keeping the atom together.

What is an element?
Element is the name for the different types of atoms. Elements are basic substances that come together to form molecules.

The elements that have been identified by scientists are listed in the periodic table .The atoms differ by the number of protons they have in their nucleus. Most exist naturally but some have only be created in a lab and scientists are still trying to make more (by adding protons).

What is a molecule?
A molecule is formed of 2 or more atoms chemically joined (or bound) together. Molecules can be made of the same type of atoms or combinations of different elements.

For example: - Gases found in the air around earth, nitrogen (N2) and oxygen (O2), made of 2 atoms of the same elements


- Ozone (O3) that surrounds the earths atmosphere, made of 3 oxygen atoms
- Water (H2O), made of 1 oxygen and 2 hydrogen atoms.
- Sugars, e.g glucose C6H12O6, made of 6 carbon, 12 hydrogen and 6 oxygen atoms

Answered by Dr Sarah Newnham (Microbiologist)
 
As you probably know carbon dioxide, or CO2, is a naturally occurring molecule and is found all around us in the air. It is made of 1 carbon atom and 2 oxygen atoms, which are important elements that make up all living things. Carbon dioxide has a lot of things in many different ways here are just some of them...

- In living things such as plants, algae and some bacteria carbon dioxide is absorbed from the atmosphere. They use the carbon dioxide with water and sunlight to produce their food, in the form of sugars, giving them the energy they need to survive. This processes is called photosynthesis, it is useful to us as it produces oxygen that we need to live. Scientists are looking at ways to use these organisms (living things) to produce biofuels via photosynthesis.

- In living things that need oxygen, like humans carbon dioxide is the end product of respiration. Respiration is the name for how we make energy by breaking down sugars, fats, proteins we get from our diet. The carbon dioxide is then released into the atmosphere.

- in industry carbon dioxide is used as it is an inert, or stable, gas so it is safe for use in most environments. It is used in fire extinguishers, food and drink production, pressurisation e.g. pressure tools and bike tyres, chemical production e.g. drugs, refrigerators, etc.

Carbon dioxide does have some negative effects, such as dissolving into the oceans lowering the pH, known as ocean acidification, and it is a greenhouse gas which leads to global warming. Carbon dioxide as a waste product from industry, which is causing the concentration to increase in our atmosphere. Scientists are looking at ways to use the extra carbon dioxide we are producing, for example by using the organisms that need carbon dioxide for photosynthesis to make biofuels and chemicals.

Answered by Alex Nicholls

Most of the electrons in an atom exist in pairs that spin in opposite directions, so the magnetic effect of one electron in a pair cancels out the effect of its partner. But if an atom has some unpaired electrons (iron atoms have four), these produce net magnetic fields that line up with one another and turn the whole atom into a mini magnet. When you put a paramagnetic material such as iron in a magnetic field, the electrons change their motion to produce a magnetic field that lines up with the field outside. You have just produced a permanent magnet.

We now know that Earth is magnetic because it's packed with molten rocks rich in magnetic materials such as iron. Just like a bar magnet, Earth's magnetic field stretches out into space, in a region called the magnetosphere, and can affect things around it. When energetic particles zooming in from the Sun (the so-called solar wind) interact with Earth's magnetic field, we get amazing auroras in the sky, the northern lights or aurora borealis, and the southern lights or aurora australis.

Iron is the king of magnetic materials—the metal we all think of when we think of magnets. Most other common metals (such as copper, gold, silver, and aluminum) are, at first sight, nonmagnetic and most non metals (including paper, wood, plastic, concrete, glass, and textiles such as cotton and wool) are nonmagnetic too.

But iron is not the only magnetic metal. Nickel, cobalt, and elements that belong to a part of the Periodic Table (the orderly arrangement chemists use to describe all the known chemical elements) known as the rare-Earth metals (notably samarium and neodymium) also make good magnets.

Some of the best magnets are alloys (mixtures) of these elements with one another and with other elements. Ferrites (compounds made of iron, oxygen, and other elements) also make superb magnets. Lodestone (which is also called magnetite) is an example of a ferrite that's commonly found inside Earth (it has the chemical formula FeO·Fe2O3).

Magnetism is the other side of electromagnetism. If one takes a coil of wire (lots of them) and rotates it (them) in a magnetic field one produces electricity. If one takes a coil of wire (lots of them) in a magnetic field and applies electricity, one produces rotation. The two sides of the same coin..