The previous 5 posts were written by the Scitt students as an introduction to blogging during their Science/ICT day. Hope you find them useful!

Light and Dark

PLAY ALIEN ATTACK NOW!

• There are many sources of light. These include:

Sun

Torch

Candle

• Light travels in straight lines from a source. Light travels at 300,000 km per second.
• We see when light from a light source enters our eyes. We would not be able to see if this did not happen.

Try this quiz

Quiz 2

• Light can be reflected by shiny surfaces
• When white light is refracted it can be split into its component colours. These are Red, Orange, Yellow, Green, Blue, Indigo, violet (Richard of York Gave Battle in Vain).

Mixing Light Activity

• Darkness is an absence of light.
• THE MOON IS NOT A LIGHT SOURCE, IT REFLECTS LIGHT.
•  Objects in front of a light source will create shadows. The closer the object to the light source, the larger the shadow.

 Light and shadows quiz

MATERIALS:

States of matter

• Nearly everything exists as solids, liquids or gases. Solids, liquids and gases are called the three states of matter.
• Materials can be changed from one state to another by heating or cooling.
• If ice (solid) is heated, it changes to water (liquid). This change is called melting.
• If water (liquid) is heated, it changes to water vapour (gas). This change is called evaporation.
• If water vapour (gas) is cooled, it changes to water (liquid). This change is called condensing.
• If water (liquid) is cooled, it changes to ice (solid). This change is called freezing.
• There are two different types of changes (physical/chemical).
• Physical is a reversible change that can be changed back (water into ice and then back to water again)
• Chemical is an irreversible change that cannot be changed back (cooking a piece of bread into toast which cannot be changed back)

Click on the link below for the ‘Changing State’ game.

http://www.bbc.co.uk/schools/ks2bitesize/blogs/shell.swf

Electricity is energy. In your home electricity runs the lights, appliances like toasters, the television, toys and more.  Electricity travels in circuits.

Circuits need to be complete for them to work properly. This means that the circuit must go in a full loop around from the power source and back again. Circuits that are not complete will not work.

A power source can be either a cell (battery) or mains. When using more than one cell in a circuit remember that the cells all have to be facing the same way.

The electricity which reaches your home also travels in a circuit and the ‘battery’ which supplies this energy is called a power plant. The power lines (transmission wires) which carry electricity to your home are excellent electrical conductors.

Electricity is always trying to get to the ground. Like all good travellers, electricity takes short cuts whenever it can. If something that conducts electricity, i.e. YOU, gives electricity an easy path to the ground it will take it!

Game

CHANGING STATES OF MATTER

The earth is one large mixture of molecules in solids, liquids and gases. Check out the pictures to see how these are structured:

All matter can move from one state to another. It may require very low temperatures or very high pressures, but it can be done. Phase changes happen when certain points are reached. Sometimes a liquid wants to become a solid. Scientists use something called a freezing point to measure when that liquid turns into a solid. There are physical effects that can change the freezing point. Pressure is one of those effects. When the pressure surrounding a substance goes up, the freezing point also goes up. That means it’s easier to freeze the substance at higher pressures. When it gets colder, most solids shrink in size. There are a few which expand but most shrink.

Now you’re a solid. You’re a cube of ice sitting on a counter. You dream of becoming liquid water. You need some energy. Atoms in a liquid have more energy than the atoms in a solid. The easiest energy around is probably heat. There is a magic temperature for every substance called the melting point. When a solid reaches the temperature of its melting point it can become a liquid. For water the temperature has to be a little over zero degrees Celsius. If you were salt, sugar, or wood your melting point would be higher than water.

The reverse is true if you are a gas. You need to lose some energy from your very excited gas atoms. The easy answer is to lower the surrounding temperature. When the temperature drops, energy will be sucked out of your gas atoms. When you reach the temperature of the condensation point, you become a liquid. If you were the steam of a boiling pot of water and you hit the wall, the wall would be so cool that you would quickly become a liquid.

Finally, you’re a gas. You say, “Hmmmm. I’d like to become a plasma. They are too cool!” You’re already halfway there being a gas. You still need to tear off a bunch of electrons from your atoms. Eventually you’ll have bunches of positively and negatively charged particles in almost equal concentrations. When the ions are in equal amounts, the charge of the entire plasma is close to neutral. (A whole bunch of positive particles will cancel out the charge of an equal bunch of negatively charged particles.) A plasma can be made from a gas if a lot of energy is pushed inside. All of this extra energy makes the neutral atoms break apart into positively and negatively charged ions and free electrons. They wind up in a big gaseous ball.

Click on this link to do an activity on changing state

Now test your knowledge

Sound

Listen to this sound song

5F Sound Song from Simple Science on Vimeo.

Sounds are vibrations

• Sounds are nade when objects vibrate. The vibration makes the air around vibrate, and the air vibrations enter your ear which you hear as a sound.
• You cannot always see the vibrations, but if something is making a sound some part of it is vibrating.

OBJECT VIBRATES     ———————> AIR VIBRATES   ———————-> EAR DRUM VIBRATES

Sound vibrations can travel through different materials

• • Sounds as vibrations can travel through many different materials. They can travel through solids such as metal, stone and wood. They can travel through liquids such as water and they can travel through gases such as air.
  • Sound vibrations travel better through some materials than others. For example, sound vibrations travel very well along metal pipes.
  • Sound cannot travel through a completely empty space (a vacuum), which has nothing, not even air, in it. If there is a vacuum between a sound-making object and our ears, we won’t be able to hear the sound.

Pitch of a sound

• The pitch of a sound is how high or low the sound is. A high sound has a high pitch and a low sound has a low pitch.
• When plucked, a short string gives a higher-pitched sound than a long string.
• When banged, a tight drum skin gives a higher-pitched sound than a loose drum skin.

Loudness of a sound

• The loudness of a sound is how loud or soft the sound is.
• A guitar string plucked strongly makes a loud sound. A guitar string plucked gently makes a soft sound.
• A drum skin hit hard makes a loud sound. A drum skin hit gently makes a soft sound.
• A recorder blown hard makes a loud sound. A recorder blown gently makes a soft sound.

Take this sound quiz to test your knowledge

good luck!