A magnet has two poles, a north and a South Pole
- north poles attract south poles
- south poles attract north poles
- south poles repel south poles
- north poles repel north poles
Magnetic materials will experience a magnetic force when placed near a magnet, this is a type of non-contact force as the materials do not have to touch for the force to be apparent
There are 3 magnetic metals these are iron nickel and cobalt
- Electro magnets are made by wrapping a coil of wire around a magnetic core
- Electromagnets only work when electricity is flowing through the coil, which means that they can be turned on and off
- Electromagnets are also stronger than permanent magnets
- The electromagnet will produce the same magnetic field shape as a bar magnet
Within the topic of physics the term work done refers the the transfer of energy when a force is used to move an object a certain distance.
like energy, work is measured in Joules(J)
work done can be found in a range of situations e.g. lifting a cup, work is done against gravity, When you write with a pen work is done against friction
Radiation is a method of transferring energy without the need for particles.
Fun fact- Helium is an unreactive substance, this is because it has a full outer shell of electrons restricting accessibility to reach the protons and neutrons.
An example of radiation is thermal energy being transferred from the sun to us through space(Where there is no particles).
Word equations can represent a chemical reaction
Methane + Oxygen = > Carbon Dioxide + water
Beneath this here is an example on how to balance an equation.
Step 1: The Unbalanced Chemical Equation
The unbalanced chemical equation is given to you.
Aluminum reacts with oxygen to produce aluminum oxide.
Rewrite the equation as shown above.
Step 2: Make a List
First, identify the elements on the reactant side(left side) and the elements of the compound are on the product side (right side).
- make a list of all of the elements on each side under the equation for both the reactants and products as shown above
- Under the reactant’s side, list Al and O
- under the product’s side, list Al and O
Step 3: Identifying the Atoms in Each Element
An atom is the smallest component of an element that contains chemical properties of that element. The atom of each element’s contains the protons, neutrons, and electrons of that element.
The list made of each element on both the reactant and product side will further help you identify the number of atoms each element contains.
Next to each element of the list, put the number of atoms that are in each of the elements.
- on the reactants side, next to Al, put 1
- next to O, put 2
- apply these same rules to each element on the product side
Step 4: Multiplying the Number of Atoms
Notice how the number of atoms next to each element is different from the number of atoms next to that same element on the product side.
In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.
As shown above, the multiplication of the atoms on the reactant side will affect both elements on the product side.
Step 5: Placing Coefficients in Front of Molecules
After you have multiplied the number of atoms of each element until both sides are equal, you will put the number, the coefficient, of how much you multiplied the element by and place in front of that element or compound in the equation as shown above.
- On the product side, although both elements did not get multiplied, still place the number that was multiplied as the coefficient in front of the compound.
Step 6: Check Equation
After you have placed the coefficients in front of the molecules, make the list of elements again and check to see if multiplying the coefficient with the subscript will give you atoms equal on both the reactant and product sides.
If they are not equal, rework your multiplication.
Step 7: Balanced Chemical Equation
After you have reworked your multiplication, make the list of elements again to check to make sure the equation is balanced. If both sides are equal, you have now balanced the chemical equation!
Genes And Natural Selection
There are many things that animals compete for these are from food, space, water and mates. These can be made easier by evolution where these animals evolve to better fit there surroundings. This is a phenomenon known as natural selection. Here is a further description (look bellow!)
Members of the same species have a natural variation in their genes. Some of these genes will give these members an advantage to suit their environment. These members are more likely to survive and reproduce- passing on these advantageous genes (natural selection leading onto evolution)
Charles Darwin was a famous scientist in the 1800 because he came up with an idea that would change the world for ever. This idea was Darwin’s Theory Of Evolution
Darwin concluded that if a bird was born with a beak suited to the food available on its island, it would survive for longer. Therefore, it would have more offspring, and pass on this advantageous gene. Overtime the population of birds on that island would all have this characteristic. Darwin called this process natural selection.
So from this I theorised that we as humans come from apes as over millennia we have evolved from many advantageous genes to become what we know today as the modern day human.
Fun fact- Alfred Wallace, was working on his own theory of natural selection and evolution. Wallace and Darwin read each other unpublished work so they could compare ideas. Their ideas were so similar that they jointly published the theory of evolution in a scientific paper.
kinetic energy
Above is the formula to calculate kinetic energy, used in physics more specifically the area of energy. A example question could be…
eg.
If the mass of a car is 100 Kg and its going at the speed of 5 m/s what is the kinetic energy?
K= 0.5 X 100 X 5(2)
Answer= 1250 K
Gravity Potential Energy
Above is the formula to calculate kinetic energy, used in physics more specifically the area of energy. A example question could be…
eg.
What is the GPE of a car if it weighs 100kg is 20 m tall and its on earth(so the GF is 9.8)?
GPE= 100 X 9.8 X 20
Answer= 19600
Kinetic energy and gravitational energy are two important types of energy that show up in everyday life. Kinetic energy is the energy an object has because it’s moving. When a car speeds down the road, it has a lot of kinetic energy. The faster it goes, the more kinetic energy it has. You can feel this if you’ve ever tried to stop a moving object, like catching a baseball. The ball’s speed (and mass) gives it kinetic energy, and stopping it takes effort because that energy has to go somewhere.
On the other hand, gravitational energy, also called gravitational potential energy, is the energy an object has because of its position relative to Earth or any other large object that has gravity. Imagine holding a book above the ground—gravity is pulling on it. The higher you lift the book, the more gravitational energy it has. This energy is “stored” in the object because if you let go, gravity will pull it down, and it will fall, releasing that stored energy as kinetic energy. The energy changes from gravitational to kinetic as it falls, picking up speed and gaining kinetic energy until it hits the ground.
So, kinetic energy is about movement, and gravitational energy is about height and gravity. They’re connected because gravitational energy can turn into kinetic energy whenever something drops, like when a skier goes downhill or when water flows from a high dam.
Gravitational potential energy (GPE) and kinetic energy (KE) are two types of energy that are constantly being converted back and forth. Gravitational potential energy is the energy stored in an object because of its height above the ground. Think about a roller coaster at the top of a hill. While it’s sitting still up there, it has a lot of GPE because gravity could pull it down at any moment. The higher the roller coaster is, the more gravitational energy it has, since it has a greater distance to fall.
Now, once the roller coaster starts going down the hill, its gravitational potential energy begins to change into kinetic energy. Kinetic energy is the energy of movement, so as the roller coaster speeds up, it gains more KE. By the time it reaches the bottom of the hill, most of its GPE has turned into kinetic energy, which is why it’s moving so fast. This is the same reason why when you drop a ball, it starts out slow but speeds up as it falls; gravity is pulling it down, turning its stored energy into motion.
In nature, GPE and KE are always interacting this way. For example, a river flows downhill because of gravity, converting its gravitational potential energy into the kinetic energy of flowing water.