Light & Electron Microscopes

 There is a difference between Light and Electron microscopes, most microscopes we use are light microscopes which are lighter in weight cheaper to purchase and easier to use than electronic ones. But that comes with some drawbacks, as we can only see stuff that is 0.2 micrometres so our resolution can only go to 0.2 micrometres because light has a wavelength of 0.2 micrometres and we use the light to focus on the subject, 
and if we try to zoom in further than 0.2 micrometres it will be unfocused and blurry.

While electron microscopes are heavy, expensive and hard to use, and only really used by scientists, election microscopes use electrons instead of light which enables you to zoom in until 0.1 nanometers, electron microscopes have a nearly 2000x zoom compared to light microscopes.
They are normally used to look at sub-cellular structures, so you can look at the nucleus of cells along with the mitochondria, but they also have no colour and thus are black and white since that there is no light going into the subject. 

Conduction, Convection & Radiation

If you heat up any object, energy is transferred between the heat source and then into the object's thermal energy store, thus increasing its temperature.

Heat is transferred by Conduction via solids, Radiation via empty space or the air, and finally, Convection by liquids.

For objects to be heated up using conduction, vibrating particles transfer energy to other particles via kinetic energy, since they are being heated up and the heat excites them causing them to move extremely fast.
causing heat to disperse throughout the object, this is why when you heat up a metal rod.
Heat creeps around and eventually causes the metal bar to roughly be the same temperature regardless of where the heat is coming from. 

Different materials can take in various amounts of heat depending on their thermal energy stored, and how well they can conduct heat is their Thermal conductivity, so metals have better thermal conductivity compared to something like plastic which has low thermal conductivity.
That is why we use plastic as insulators for heat in tumblers and bottles when storing hot or cold water, as it traps heat better.

Let’s take a beaker fill it with water and put a Bunsen burner below it when you heat up the liquid or gas, the particles at the bottom will start moving around, and they naturally want to move to a place cooler, the fluid or gas in the warmer region starts to heat up and expand.
Let's go back to the beaker, if we heat up the bottom with the bunsen burner the warm particles at the bottom will want to rise up and get to the cooler region which is the top of the beaker

Conservation of Energy

The first law of Thermodynamics is that energy can be transferred, stored and dissipated but cannot be created nor destroyed.

For example, when you plug your phone into a socket to charge it, electrical energy is turned into chemical energy in your phone's battery. And using the chemical energy that was being charged by the electrical energy from the socket to power things such as the screen which turns the chemical energy into light energy, or play sounds by converting it into sound energy. 

But you can never have 100% energy transfer, it's because there will always be wasted energy.
Most wasted energy is lost due to the energy generating heat, like when you are charging something your phone gets warmer, or a car tyre is spinning rapidly causing friction which causes the tyre to get warmer.  

There are types of systems: closed and open systems. First, we have to select one. Let's say we take your phone as a system. The system would be the phone, while the outside world would be named the "environment." In this case, the phone would be an open system because it can be affected by the environment or outside factors. Because this is an open system, energy can flow between the environment and the system.

While a closed system stops all outside factors or the environment entirely.
If you put your phone in a sealed jar. Everything inside the jar is the system, and because it is in a sealed jar it is not affected by outside forces or environment factors.
So when the phone heats up, the heat is trapped inside the jar and it stays within the system.

Balancing Chemical Equations

Chemical equations are very important for written Chemistry, for example, if we take Methane + Oxygen -> Carbon Dioxide + Water, the underlined words are products, while the non-underlined are not.

Now to write this as chemical symbols you would write it as:
c
the Ch4 is because there is 1 carbon and 4 hydrogen. For the O2 it is because O2 is 2 oxygens.
While the products CO2 + H2O, has the CO2 has 1 carbon and 2 oxygen, while H2O has 2 hydrogen and 1 oxygen. 

Now if you want to "balance" these equations, it is mainly done by trial and error, it is because you can't change the subscripts because it changes the whole element to a completely different one.
But we can change how many of the elements there can be, to balance the
Ch4 + O2  -> CO2 + H2O.
In order to make the equation "balanced" we must match the number of oxygen atoms at both sides.
So if we look at the reactants we might notice 

Microscopes

Light microscopes are highly important in Biology because they allow you to see the smallest things like cells.

First lets start with the base, which connects to the arm, then there's the "Stage" which is where we put our objects on to examine them. 
Usually there's 3 objective lenses, with different magnification strengths, then there's the lens at the top which is where our eye goes and has a fixed magnification, then the tube which goes from the lens at the top to the lenses at the objective lenses,
then the coarse and fine focusing nobs to focus the lenses on the object on stage.  

Let's get this straight, there are two things that are important when looking through the magnifying glass (there's more but that doesn't matter right now), mainly the "image" and the "object".
When referring to the object you are usually referring to the object or sample you are looking at on the stage. So if we have let's say onion cells on the stage, that would be considered to be the "object" or "sample". 

The term "Image" comes from the image that we see when we look down, we see the individual cells, and what we see in the lens is the image. 

Light Microscopes work by shining or reflecting light onto the subject.
Or by using an adjustable mirror below the stage or by turning on a lamp at the bottom to illuminate the clear stage. 

First, the light shoots up towards and through the sample, then through the objective lenses, then through the tube then into the lens where our eyes are.
This, in turn, is necessary for the light to bounce off objects for our eyes to see, magnification happens when you magnify the object, so an x100 magnification means the object is magnified 100 times. 

Resolution means how detailed the image is, so if an object has a terrible resolution it is very blurry, while a good resolution is good when it is crystal clear and very sharp. 

Differences Between Compounds, Molecules & Mixtures

 Mainly elements fall into 3 categories, Molecules, Mixtures and Compounds.

Molecules refer to elements bonded via chemical bonds, a good example of this is Oxygen, which is bonded together so they are classified as a molecule, but these molecules can also be made of multiple different elements, such as water which is H20, others being Hydrogen, Chlorine and Carbon-dioxide. Molecules need 2 or more elements in order to be considered a molecule.

A Compound is made out of two elements held together by chemical bonds, for example, water is also considered a compound because it contains hydrogen and oxygen.
Along with carbon dioxide because it is made out of oxygen and hydrogen. But water, chlorine and hydrogen are not considered compounds because they only have one unique element.
Another thing about compounds is that they are found in the same proportions, so you wouldn't see a water compound with one more hydrogen. Water will always have two hydrogen atoms and one oxygen atom. And it is consistent and never changing.
Since it is consistent water will always be H2O. Now the smaller 2 is written in a "subscript" which signifies that the H in the water molecule is that there are two hydrogen atoms, and carbon dioxide is always going to be CO2, the 2 being that there are two oxygen atoms. 

Another element is H2SO4, which always has 2 Hydrogen (H2), one Sulfur (S), and four Oxygen (O4).
But for some elements, Calcium for example: Ca(OH)2, the calcium is made out of one Calcium atom (Ca), and two of OH or (OH)2. 
These atoms are actually very small as some atoms contain up to a billion atoms, like table salt or Sodium Chloride which has the elements NaCl.  
But unlike other atoms, sodium chloride has as large structure compared to other atoms, sodium chloride has an Ionic bond, and the NaCl or table salt is a 1:1 ratio, so that if there's a Na atom there is always a Cl atom.

Mixtures are substances that are not bonded together. So if we combine sodium chloride, oxygen, individual helium atoms, and carbon dioxide this would be considered a mixture, 

Internal Energy and Heat Capacity

Internal energy usually comes into two forms: Potential Energy stores, and Kinetic Energy stores.
Most potential energy stores come from Gravitational and Elastic energy, this isn't really related to temp but is good to know. Kinetic energy on the other hand is very important as the movement is an energy store.

When you heat up anything, you are converting the heat into kinetic energy stored which we can measure in an increase in temp, which is a measure of the "Internal temperature" of a substance.  

However, substances need more energy to increase their temperature than other elements, as water needs 4200J or 4200 joules of heat in order to warm 1kg of it by 1°c. 
Compared to Mercury which only needs 139J of energy to have 1kg of it to be 1°c  hotter. These numbers are called "Heat Capacity."
The inverse is also true, so when water cools by 1°c, the water is relicensing 4200J of energy while cooling.