Hamish Astra (11) asked “What are electrons and protons and neutrons made of?”

What a question. I suddenly feel very humble because that is a question that I should have asked myself but I never have. Thank you. I asked my friends to help me and here are the responses.

I have, discovered that electrons are still fundamental particles BUT they have found two types of electrons a negatively charged electron and a positively charged electron so they are now called leptons.  That does not however answer your question. What is a lepton made of?

My friends are quite correct Protons and Neutrons are no longer fundamental particles. (A fundamental particle is a particle that is not made of anything else) It was in 1911 that a scientist called Rutherford first discovered the proton and neutron. Then,in 1968, other scientists found that protons and neutrons were made up of fundamental particles called quarks. The next question of course is what are quarks made of?

To be continued

“How, where or when we’re magnets found or made?” asks Sam (11)

Thanks for the question Sam. Magnets and magnetism was first discovered about  9000 years ago. A long time ago. It was found in rocks and called ‘lodestone’. Lodestone is a naturally occurring compound of iron. It is thought that it was magnetised by lightning strikes.

We will make our own magnets by using a slightly weaker form of electricity.  Here are my team.

Firstly let us try to make a magnet (without using lightning)

You will need a battery and a length of wire and some paperclips. The a collection of nails. Try and find as many different nails as you can. Wrap the wire around the nail and sellotape the bare wire ends to the terminals of the battery. See the diagram below. See how many paperclips you can pick up? Are some nails better than others?

DO NOT USE MAINS ELECTRICITY. IT IS VERY DANGEROUS. 

You might have found out that only certain metals can be made into magnets. These metals are called ferromagnetic metals.

Included in this group are the metal iron and the alloys of iron with the metals cobalt, nickel.

It is thought that in these metals (including iron) have some electrons called ‘free electrons’ (not sure what an electron is, then go to Science Master Special – Atoms and Atomic Structure). It is these ‘free electrons’ that are involved in magnetism. In the alloys the  ‘free’ electrons align themselves with the magnetism of the external magnet, making a (for the alloys) a permanent magnet.

Look at the short video I have made below. In the ferromagnetic metal (iron alloy) crystal domains you will see free electrons. In the metal these will be moving freely. As they begin to interact with the external magnetic field, they begin to align themselves, making a permanent magnet.

Ronan (10) asks “How do stars form?”

Ronan ..this is my thinking about your excellent question.

Yes it is all about Gravity – There was a previous question by Tegan on Gravity. Have a look at it.

It is thought (it is therefore a hypothesis – an unproven idea)  that dust and hydrogen gas from the ‘Big Bang’ was gravitationally attracted to each other.

As the mass of the dust and gas got bigger it’s gravitational pull got bigger and the more dust and gas it attracted.

Eventually  the compact squashed ball of dust and gas started to heat up. It got hotter as it got bigger and eventually the particles of dust and gas began to break up in this hot environment and the hydrogen particles began to come together to make new particles … an atomic FUSION reaction began to occur and the star was born.

What does a dead star turn into? asks Liam (9)

Liam. Science is an interesting area of knowledge. It is recognised that it originates from an area of study called Philosophy. Philosophy (an Ancient Greek term) is about asking questions and for Science it is about asking questions about the physical and biological world. We ask the question and try to find the answers. For your question the answers are not easily found.

To try to answer your question, we have to know a little bit about the Sun. We know that in it’s centre there is an atomic reaction going on. It is not the type of atomic reaction we have in our Atomic Power Stations where we have an atomic ‘fission’ reaction occuring.

‘Fission’ means splitting something into two or more parts. The animation below shows a small atomic particle called a ‘neutron’  hitting a much bigger particle called an ‘atom’ . It splits forming more neutrons that hit other atoms, which break and form more neutrons………and on and on. This is a fission reaction and a lot of energy is released.

In the Sun the opposite is happening. Instead of fission we have fusion , the joining up of particles (Hydrogen atoms) to give Helium which creates lots and lots of energy. See the diagram below.

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Why would the Sun die? The main reason is that it runs out of Hydrogen. So what will happen then?  Firstly the Sun will get brighter. This will happen because of the helium that is produced. It will be pulled into the centre and begin to burn, adding more light and heat to the Sun’s radiation. Then as the hydrogen gets less and less the Sun will get cooler but at the same time begin to expand. It will become a Red Giant.

It is reckoned that it will expand so much that it will consume the Earth……that will happen in about 4 billion years time, however life on Earth will no longer exist in 1 billion years. This is because of the brightening of the Sun and the rising temperature of The Earth’s atmosphere, all the oceans will disappear and plant life will not be able to survive.

 

 

 

Science Master Special – Atomic Structure

This is a great video describing atomic structure.

And here is an example of the structure of an iron atom.

Note that most of the electrons are ‘paired’ with the exception of a few ‘free’ electrons in the outermost orbit.

Questions on electricity were asked by Gavin (10), Tegan (10) and Hayden (9)

Gavin asked “Why does the energy flow through the wires?”

Tegan asked “How does electricity work?”

Hayden asked “How do batteries springs and wires make a complete circuit?”

So how does this compare with a modern day battery. lets have a look and think about Gavins question.

Hayden and Tegan. In the circuit below the  energy flows around the circuit when the switch is closed. Why? What are wires made of? What is special? If the wires were plastic do you think electricity would be able to pass through it? Try and make your own circuits with different materials.

Electricity is linked to the passage of negatively charged electrons. These were very comfortable in the battery until it was connected to a circuit (a circuit is a continuous pathway) and the switch was closed. The circuit gave the electrons (negatively charged) a passage to the positively charged end of the battery. Electricity (electrons) flowed and accompanying the electrons was energy. Look at the Science Master Special on Energy and why not try the Circuit Quiz.

 

Do not play with mains electricity. It is very dangerous and could kill you.

“How do compounds and elements work together?” asks Candice (13)

Thanks for that information team. It does illustrate the relationship between elements and compounds and the way in which they work together. To understand this a little more you will have to know  more about the structure of  the atoms which make up the elements. All of the atoms of the 118 elements have a different number of protons in their nucleus and this dictates the way in which they behave in the formation of compound.

Below is a drawing of an atom of the element Lithium with the electrons, protons and neutrons.

I hope this gives you some answers to your question. If not please comment or ask another question.

PS  You and your friends might be interested in the crossword puzzle background. Its all about atoms, elements and compounds. You can download the crossword and the answers from the link below.

Crossword.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Andrew (11) asks “How do you make plasma?”

Andrew, quite an ‘exciting’ question. To find out how we make plasma lets look first at atoms and their structure. My team will do this and then I will come back to talk about plasma.

Andrew. I will be talking about a Neon atom. The Neon atom has 4 protons in its nucleus with 4 electrons orbiting it. Does that give you a clue to my plasma source?

The most familiar plasma sources that you might come across are Neon light tubes and lightning.

Firstly let us look at what plasma is. It is defined as a hot ionised gas which has an equal number of protons and electrons existing in the same space. Lets look at a neon light tube.

In the tube the Neon atoms lose electrons to the positive electrode, the remaining  Neon positively charged atoms (they have lost an electron) are attracted to the negative electrode. Lots of exchanges of electrons take place during this process and this ‘excites’ the electrons and creates the  plasma environment which gives of energy in terms of light.

Really hope that this helps. Please tell me if you do not understand bits of it or ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

 

Edited 11/10/2017 Pictorial representation in image changed to ‘drawing’. Text size on image changed.

Science Master Special – atoms, molecules, intra and inter molecular forces, heat energy and kinetic movement

There is a bit of everything in the title. Maybe the basis of everything as we know it up to now.

    • Atoms are the foundation of our understanding of matter (all the stuff around us).
    • Molecules are the the building blocks that are constructed from atoms to build the stuff around us.
    • The forces between atoms that make up the molecule are called intramolecular forces.
    • The forces between the molecules that the atoms make are are the intermolecular forces.
    • The study of molecular kinetics is the study of the movement of particles and the movement is usually associated with applied heat. Heat energy and movement are strongly linked. Heat something and it moves faster.

For a more detailed look at the structure of atoms look at this Science Master Special

Any questions?

If you have any please ask them in the Reply section below.

Science Master Special – States of Matter (a role play)

This is a role play which I think can give you younger learner some ideas about the connections between solids liquids and gases. Try it with some friends.

There are only two roles: (1) The Director (2) The actors or water particles (molecules).

What is needed:  (1) Space to act out the role play (2) Temperature prompts for the Director [-15oC, -10oC, 0oC, 10oC, 30oC, 50oC, 80oC, 100oC]

To start the temperature is -15oC. The water particles are stationary (frozen) connected to each other by bonds (Hydrogen bonds-see below). The actors depict this by holding hands with the the other actors.

At -10oC the crystalline bonding is still holding BUT the molecules are slowly vibrating but still remaining in the same place.

As the temperature approaches 0oC things start to happen. The water molecules begin to move, slowly. The actors are not holding hands but have some contact with each other. The hydrogen bonding is still there.They can move from one molecule to another but must never lose contact …moving slowly. They are now liquid water molecules.

The temperature slowly increases and as it increases the water molecules are getting more and more energy from the heat source and begin to move faster. They are moving faster BUT still in contact with other water molecules. At 30oC one or two of the water molecules break away and then come back again.

At 50oC one water molecule escapes completely and doesn’t return. The rest are moving even faster.

At 80oC several molecules break away and maybe one returns. At 100oC the whole group begins to break up and move into the room they are now water vapour molecules and not connected at all to each other.

Hydrogen Bonds

The water molecule is an interesting particle. It consist of a central Oxygen atom and two Hydrogen atoms connected to it. The structure gives the Oxygen atom a small negative electrical charge, the Hydrogen atoms have a small positive charge. This means that the Hydrogen atom of one molecule of water can be attracted to the negatively charged Oxygen atom of another water molecule. This is your Hydrogen Bond.