Science Practicals

Every week, we go to the science lab to do some science experiments on the topics that we have learnt about such as experiments on solutions, seperation techniques-filtration, magnetic and distillation. These experiments allow us to understand more on the topic as we get to do hands on activities on them. These science praticals also allows us to learn more on the topic. We get up in pairs and work on the activity on our own, with our teachers guidance. This is a very innovative and interesting way of learning .

Solution vs Suspension

So, what's the difference?
Well, a solution is a mixture whereas the solid substance has dissolved in the liquid substance, which would make up the solvent. A solution cannot be seperated by filtration as the solute has dissolved in the solvent. Solutions that contain the maximum amount of solute in the particular amount of solvent at a particular temperature is known as a saturated solution.

However, a suspension is a mixture whereas there are solid particles suspended inside the liquid solution. It is also a heterogeneous fluid. It can be seperated through filtration, unlike a suspension. Examples of suspension are like milo.

Separation techniques

Separation techniques are very useful to separate substances from each other. Physical techniques such as distillation,filtration,evaperation and crystallisation can seperate mixtures. And chemical techniques can seperate compounds, which are two elements bonded together with heat or light energy.

Distillation is a process whereby the mixture, which contains liquid substances with different boiling points, is heated at its different boiling points, where the liquid with the lowest boing point would evaperate. The liquid would then condense on the condenser and slide down into a beaker.

Filtration can seperate a solid from a liquid. Firstly, you place the mixture into a funnel with the filteer paper. As time pass, the liquid would filter through the funnel a drip into a beaker. This is how to seperate a solid and a liquid(fluid)

Evaperation is a process whereby the mixture(solution) is heated until dryness. Usually, a hot water bath would be used as to have a smooth boiling. The final product would be the solute, which in a salt solution, would be salt. This process can only work for solution where the solute will not decompose.

For such situations, the process crystallsation would be used. This process is alike to evaperation to dryness, just that before the solution is completely evaperated, the solution would be allowed to cool. Thus, the solute would not decompose.

Energy

Energy comes in different forms.There is light,heat,kinetic and chemical potential energy. Energy is needed to work.

Light and Heat

The main source of light and heat energy is the Sun. As the earth is not too far, nor is it too close, from the sun, the light and heat energy received is just right for life on earth. If we were too close, it would be too hot to live on earth.The light energy also allows us to see. Thus, both light and heat energy are important

Kinetic

Kinetic energy is also known as movement. It is motion. Examples of kinetic energy is like a moving car, or a bouncing ball. The mass of the object and the speed of the object both affect the amount of kinetic energy the object has.The greater the mass, the greater the amount of kinetic energy. The greater the speed, the greater the kinetic energy.

Chemical potential energy

Chemical potential energy is the energy stored in living object, or use to be living object. It can be converted into other forms of energy. Plants trap sunlight to make food, which is chemical potential energy. Fossil fuel is burned to produce electricity. This energy allows us to do work.

Pressure and force

What is pressure? Pressure is the amount of force appliecd perpendicular to the surface of an object. To find area, the formula( Force(N)/Area(m2)). If the area increases, the pressure decreases and vise versa. If the force increases, the pressure increases, and vise versa.

So, now, what is force? Force is a push or a pull. Although force cannot be seen, but you know that a force is acting on it as there is an effect on the object. A force can move a stationary object, stop a moving object, change the direction of an object, accelerate a moving object and change the shape of an object. Example of a force is gravity, friction, magnetic force and elastic force. Gravity is the force that pulls us down back on earth. If there was no gravity,we would not be on the ground. Friction is the force that opposes motion. It goes in the other direction as the moving object. If there was no friction, the object would not stop moving. To reduce friction, lubricant can be applied on the surface.Elastic force is the force when an elastic object is streched. The force would force the spring, or elastic object, back to its original shape. Finally, magnetic force is the force of attraction or repulsion between two magnetic objects. Thus, magnetic force can either be a push or a pull. Also, magnetic force can act at a distance.