Chemistry pt. 8: Covalent bonds

 Instead of stealing atoms, let's share them.

Let's take an Oxygen atom, it has 6 valence elections. And let's take another Oxygen atom with 6 valence elections. Now these atoms would love to gain or share an electron to make themselves stable. Now sharing these elections causes these Oxygen atoms to stick to each other.
Also known as a Covalent bond, which is a type of bond that is a fusion of two atoms. And it can make atoms more stable. 

Now what about water, how does Hydrogen bond with Oxygen, once again Oxygen has 6 valence electrons. But Hydrogen has 1 valence electron, water requires two Hydrogen and one Oxygen or H2O. 
Now to explain this more easily, the Oxygen atom in this case has 6 valence electrons and the Oxygen atom shares two of its valence electrons, and both of the Hydrogen atoms share their single valence electrons. Now the Hydrogen atoms bond with the two shared valence electrons.

Molecules are 2 or more atoms that are Covalently bonded together, some molecules that are covalently bonded are:
O2 or Molecular Oxygen, H2O or Water, CO2 or Carbon Dioxide, CH4 or Methane, and NH3 or Ammonia.

But there are differences between elements as you well know, for example.
A canister of O2 and a water bottle of H2O is very different.

Diatomic elements are elements that cannot be found in nature and are. Covalently bonded together, like O2, other diatomic elements are: H2, N2, F2, Ci2, I2 and Br2.
These diatomic elements are considered Molecules but not compounds. As compounds are two different elements bonded together.

Certain Covalent bonds are done through a network, one example of a covalently bonded element is Silica or SiO2, which is mainly found in sand, a Silica covalent bond are made with Silicon and Oxygen atoms.
For the formula of Silica, there are two Oxygen and one Silicon atom.

A salt is an atom that is both Ionic and Anionicly bonded together, like Sodium Chloride, or commonly known as table salt, 
as a Na+ ion will attract all Cl- and Cl- ions around it.

As stated above a compound is two different elements bonded together, these can either be bonded ionically or covalently, H20 or water is a covalent compound because it has two different elements bonded together, NaCl is a ionically bonded compound. All salts are compounds, but note that not all substances are compounds. For example, Helium is made of He atoms, and is not a molecule or a compound, and Oxygen gas, O2 is comprised of Oxygen atoms, but not a compound, or a molecule.

 

Highschool Physics pt. 2: Distance and displacement introduction

 Let's take a sheep, a small innocent sheep, and let's watch as it follows and eats the grass. And let's watch it as it travels 10km east, and 5km south, and then another 10km west.

Now depending on how you interpret the movement of the sheep, there are two reasonable answers, one is it's "Distance Traveled", to do this equation it is 10km + 5km + 10km, which would be 25km. As you are adding all the numbers together.

Now if you wanted to find the "Displacement", the 10km east, and the 10km, west would cancel out. And that would leave the sheep 5km south from where it started. 

Ok what about a number line, lets say an orange, starts off at 0, and rolls to point 2, so that's a +2 to the right, and then lets say it rolls -3 to the left, and another -1 to the left. 
So for distance travel, you are going to add all the number up, reguardless of the minus or plus, so the distance travelled is 6 (2+1+3). 
But what happens if you want to find displacement well then the answer is -2 (0+2-1-3). 

History pt 7: Early Civilizations

The most notable way of finding out if an early civilization was highly developed, was its amount of surplus food. This makes it so that everyone doesn't need to focus on gathering as much, and can use their time instead to do other activities, that increasing production and trading with other settlements.

The first civilizations were in locations that could support intensive farming.
Governments would control certain areas and resources and use writing and religion to maintain control and create hierarchies over large land spans. Writing whether in stone tablets, parchments, or bark, writing helped keep track of laws and record keeping for later generations.

Most modern cities have supermarkets, where you can practically purchase any kind of produce, making government and specific work possible along with these markets, comes a reliable and predictable food source. 

A civilization is a complicated society allowing for specialised labour, and a large social hierarchy, a very simple civilization would be a hunter-gatherer tribe or group. While a more complicated civilization has more split roles for different people. 

The first civilizations came about in Major river valleys where the soil was already damp and easy to plant, these were called Foundational civilizations. Throughout human history, we "borrowed" other aspects of other civilizations by war and conquest. For example the Romans and the Greeks. Both have very similar practices and similar beliefs.

Cities were and still are a vital part of human advancement as people come to cities to work, trade, study and live. Having shared language, governments and beliefs helped these cities to function. And large gatherings of people in cities help foster jobs like, priests, scribes, and governing figures. 

Cities are large communities comprised of religious, political and social structures. And if a city gets too big, the city would be split into: "States". Most civilizations were unified under the banner of religion, beliefs that explain existence's meaning. Being both a political leader and a religious figure would be common and strongly connected.
For example, in Ancient Egypt the kings, later known as Pharaohs, practised Divine kingship, which stated that they were kings as well as human incarnations of certain "Gods".  

Political and Religious groups had different powers and impacts on the population. While the Political or government powers could send people to war. But the Religious side could communicate to the population and its god or gods.

Social hierarchy was a vital part of civilizations increasingly becoming more complicated the greater the population increased. Such as sculptors and artisans who decorated the cities. Merchants who sold goods and traded with other civilizations. Or the lower class for their labour and working on less specialized work in some social hierarchies slaves were kept clean and kept places tidy. 

As writing Cuneiform or stone tablet writing was important for keeping records and managing complex institutions. In Ancient China "Oracle bones" were used to predict the future. Along with the Quipuf being knotted string meant to do calculations and to keep records. 
The Ur-Nammu from Sumer was written around 2100 - 2050 BCE and the Code of Hammurabi from Babylon was written around 1760 BCE. 

Even though you needed to have a good education to read and write. Laws and rules were still written as it was easier to maintain consistency over large groups. 

Another part vital part of ancient culture was "Monumental" structures. For political, religious or for the public to view. For example, the pyramids of Egypt were monuments for their deceased rulers. 
In Mesopotamia, the Ziggurat. 
Walls and sewer systems added defence and sanitation to daily living. 

Most cities were built on gender, wealth, and labour, and intensified social hierarchies, and some built powerful and destructive armies funded purely by taxing the civilians. 

As civilization is hard to define, and arguments are plentiful about what is considered a civilization. Lets take the Niger river valley, they were able to farm large amounts of produce, urbanization, and certain labors.
But they did not create lanuage, or a new writing script, and it is extremely tough to gauge, when one civilization starts and ends.

Highschool Physics pt. 1: Foundational Physics

 The main "Foundational thinkers" of physics are Isaac Newton, Max Planck, and Albert Einstein. 

When you start learning Physics, you are studying how Newton understood it, he developed the law of gravity, Newton's law.

Down the line, we will learn about tiny things, and Max Planck will teach about Quantum Mechanics. Albert Einstein will teach about the speed of light, and that nothing can travel faster than it.

And we start realizing that the universe is bigger than we could ever imagine. 

Physics can be intimidating, as math is necessary, as Algrabra, Trigonometry, and Pythagorean theorem, are necessary. But is not 100% required, as you can still do physics calculations, but it might be strange or confusing without the basic principles.

Now let's talk about Vectors and Scalars, a vector is something that has a magnitude or a size and has a direction. While a scalar only has a magnitude or size.  
I will explain, that let's take a brick on the ground and move it 5 meters to the right, this is a scalar because you only know the size of the movement. 
But if you were to use a vector, you would say the 5 meters, and you would say to the right, as you gave it a distance or "displacement".
To recap, distance is a scalar quantity, while displacement is a vector quantity. 

Vectors can also be used to explain the speed or velocity of an object. Let's say you time the brick travelling 5 meters. And lets say you took 2 second to move the brick 5 meters. to calculate the speed you are traveling. You do the 5 meters divided by time. so 5/2, 5 for the distance, and 2 for speed. and after you do 5/2, you get 2.5 m/s or 2.5 meters per second. I don't see a direction here, but it shows no direction so it is a scalar quantity.

So if you are talking about change in position and specify the change in position with a direction that's displacement, if you don't specify the direction that's distance, and if you specify the direction and speed that velocity, and if you don't give a direction you are talking about speed.

Chemistry pt. 7: Ionic bonds

 Let's use the group 1 element, let's use sodium. We can use a Lewis dot structure, to visualize this we just draw the element of Na in the middle and draw a single dot on it, the dots on the Lewis dot structure or Lewis diagram mean the number of valence elections.

Let's take two atoms, one Sodium and one Chlorine atom, now Chlorine has 7 valence electrons while Sodium has one, the Chlorine really wants to become a "full atom", meaning 8 valence elections or zero electrons, and the Sodium also wants to be a "full atom" by removing an atom. So what happens if the Sodium gives its valence electron to the Chlorine thus both of them being a full atom.
And since now Chlorine has 8 valence electrons so now it has a negative charge, while Sodium has a positive charge, and what did we learn in physics and in magnetism, well opposites attract.
They form a compound named "Sodium Chloride", or to common folk, table salt. 
A plus one charge for the Sodium and a Negative one for the Chlorine and combined they become a neutral charge. 
This is called an "Ionic bond"

Bonds are when two different atoms either take or give away a valence electron, they become a "bond" thus making a neutral atom combining both to make a "single" whole Ionic bonded atom.

When a neutral atom loses one or more electrons while keeping the amount of protons the same it becomes a cation which is an ion with a positive charge.
And when a neutral atom gains an electron it becomes an anion.

The elements from groups 1,2 and 13 - 18 normally form ions of one charge. So a cation is any element with the word "ion" at the end, so Na ion would be a sodium ion or a Sodium +1 atom.

Certain elements will change their names depending on if they are an anion or cation. For example, for negatively charged ions or anions, a Suflur anion would be a "Sulfide", and a negatively charged Nitrogen would be "Nitride", so what we do is we take the root name and add "ide" at the end.   

And when naming ions or cations, you just say the element and then "ion" at the end. For example Hydrogen ion.

Name the cation first then the anion last, because it comes first in the periodic table. All anions and cations must be written with the lowest integer value. 

Now let's get an example, a Possasium atom (K) is in group 1 of the periodic table so it can have a positive charge or K+1. Chlorine.

Let's take a white cation and a blue anion. One is a positive charge, while the other is a negative charge, and as we know, opposites attract. So they will want to form in ways that will maximise the attractive forces and minimize the repulsive forces. 
Now let's take an element, Rubidium Bromide if we were to separate these elements into their anions and cations. It would be a Rubidium cation and a Bromide anion. A Rubidium element has 37 elections, but since it is a cation and it has lost one of its elections, so now it looks more like Krypton, which has 36 elections.
Now the bromide anion even though it has only 35 protons is going to gain an electron and now has an election amount similar to Krypton. These two elements have the same amount of electronics, but Rubidum has 2 more electrons than Bromide. And now Rubidum will be smaller compared to the Bromide atom. 

History pt 6: The spread of Agriculture

 Let's start 11,000 years ago in what is now Iraq, Syria and Turkiye, in these countries, was barley, grown in damp soil, and began domesticating animals. Sheep, goats, cows and pigs, in all the areas we are going to learn about, agriculture was being developed independently and people invented it on their own. 

9,000 BCE - 7,000 BCE is when archaeologists had on agriculture, then we move to modern-day Sudan near the southeastern Sahara desert, and what was growing there was sorghum, which is commonly known for what is now animal feed.  

Then on the west side of Africa, what is now modern-day Nigeria, 1000 years later. People started growing: okra or ladies' finger, yams, and black-eye peas. You might notice that these are used in very traditional and cultural foods. So 8000 - 6000 BCE is when these crops started.

Now let's go to Asia, starting from 6500 BCE people living around the Yangtze River, started farming rice, or paddy and domesticated pigs buffalo, and chicken, and now we go north, and in 5500 BCE they started cultivating millet and soybeans.

Then in 3000 BCE in Southeast Asia, those people grew taro, which is a root vegetable, that has a very strong starchy flavour, along with other plants like: yam, coconuts, bananas and citrus. 
The thing that relates to all of these plants is that they are all high-calorie foods. Which was necessary as you needed high amounts of calories.
We believe that they had to study roughly what plants to grow for the highest profit or "The biggest bang for your buck", where they are doing what is now called Min-maxing, where they put in the minimum level of resources for the maximum possible profit.

Let's now go to Peru and the Andes mountains, after 3000 BCE, they started growing potatoes. (the Irish, although famous for potatoes, did not start having potatoes until Sir Walter Raleigh imported them in 1589). 
They domesticated: llamas, alpacas, and guinea pigs. And since guinea pigs were domesticated the Quechua people would eat them as a food source, and people now in Peru still eat them.

Gregor Mendel and pea plantts

 Inheritance means you "Inherit" certain traits, and that usually comes from the form of genetics, when you are born you inherit traits from your parents, maybe their eye or hair colour, their facial features, or health problems like diabetes, heart disease, or schema.

But if you were to have a sibling, and while your sibling has eczema while you don't, that's a bit strange.

Well, a person named Gregor Mendel, who was a monk in the 19th century, experimented on a simple pea plant.

Now you are probably wondering why did he not experiment on humans, one reason is that it can take decades for humans to be test subjects. As they take years to grow and mature, and can only produce a few children making data collection slow and time-consuming. A plant can have thousands of offspring has a faster growth rate, and matures much quicker. 
And also it is a matter of ethics, where it's not really ethical to ask a woman to get pregnant to see what the child looks like compared to the father. 

Using Mendel's research scientists and common folk alike can predict certain genes from their parents. Parents before the baby is born will often guess what the baby will look like. Like if the father has brown eyes, or the mother has black hair. 

Johann Gregor Mendel born from 1822 - 1884, is commonly referred to as the "Father of genetics", he was a teacher, a scientist, and a man of Christian faith.
Although his education was expensive, he graduated from both high school and university and then joined the Augustine Abbey of St. Thomas in Brno, which is now modern-day the Czech Republic.

He actually went against his father's wishes, instead of focusing on the family farm. He instead went to pursue his education and personal interests, supported by the monastery. He taught: Physics, Botany, and Natural science, at the secondary and university levels.

Then in 1856, he started his decade-long study on patterns of inheritance.
Going from mice to honeybees, to plants and settled on the Pea as his main "primary model system.
A "primary model system" is used when a researcher or scientist wants to study and use an easier specimen, such as the pea plant.
Because studying a pea plant or the model system is much easier compared to humans. By using a model system to learn the basics of inheritance, we are able to form the very basic principles of inheritance and apply them to other organisms like humans.

Mendel created these parameters to measure the differences in parent and child plants: height, flower colour, seed colour, and seed shape.
At first, he was pure-breeding them (using two parent pea plants), then after a few breeding sessions, he noted that the pure-bred plants were nearly identical to the parents, then once the boh parent plants made two children, Mendel would cross-breed the two children.
Mendel would write down the similarities between generations of pea plants and the results were they were extremely similar.

The first generation found that he found the dominant trait was tall, while the recessive trait was short. In the second generation, Mendel allowed the plants to self-pollinate. Then the hidden short trait was revealed. And appeared in the minority of plants, with a 3:1 ratio.

Mendel also found out that a plant can inherit multiple properties independently, as the height of a plant did not intrude on its ability to have different flower colours or seed shapes.

Then in 1865, he presented his findings to the local Natural History Society.
He announced his theory on inheritance with nearly 30,000 pea plants he worked on.
He presented that: There are two types of genes, dominant and recessive, as the dominant would mask the recessive gene,
the paired factors would separate during the gamete (either the sperm or egg) and one gamete would inherit one other factor. 

He then made the "Law of segregation", and in 1866 he wrote a book titled "Experiments in Plant Hybridization" in the Proceedings of the Natural History Society of Brünn.

Sadly Mendel's work was unnoticed by his peers for the value they held, and his studies went against what was believed about inheritance, Mendel's approach to biology with a mathematical perspective was seen as taboo.

Then around the 1800s the idea of "Blending inheritance" came about, and the theory that the genes that a child has "blended" genes from their parent since they look similar and similar traits are shared between parents and their children. But this theory did not explain why Mendel, when crossbreeding his pea plants crossbred a tall and short one, and the seeds from that crossbreed were mainly tall peas.
If the blending theory were to be correct, the crossbreed between a tall pea plant, and a short one, was that it would make a medium-height pea plant. But that is not the case.

As Mendel proposed, the plant's height was affected by inheritable factors which were inherited by the offspring of the parents.
But in humans, our height and many other features, inherit fractions of the parent's genes. This makes it exceedingly difficult in certain cases to notice a change affected by the parent's genes. As it is difficult to discern changes in the offspring it can appear to look like blending. 

Then in 1868, Mendal at age 42 became an Abbot for his monastery and set his studies aside to work on his pastoral duties. But his work was undervalued and mostly unknown until the year 1900 when his work was found, tested and revitalized.

The pea plant or "Pisum sativum", pea plants was the most convenient for studying gene inheritance and is still used today by geneticists to study inheritance. The key part of why the pea plant was used is that it is a self-fertilizing plant. Meaning it makes both the sperm and egg reproduce and it has the added benefit of producing a lot of seeds in its high-speed life cycle.
Thus Mendel sought to use this fact in practice, he was able to make "true" bred peas and made sure to breed them so that they always follow the parent's genes.

Along with the fact that they are easy to crossbreed, this is done by getting the pollen from the anthers and giving it to a mature pea plant in its carpal of a different variety. 
To make sure a plant did not self-pollinate. Mendel painstakingly took out all the anthers on his pea plants.

For Mendel's experiments,  he wanted to study their height and how inheritance affected the variances in height. So he set up two generations, one short, one tall.

Then Mendel did a crossbreed between one purebred short and one purebred tall pea plant, and named this generation P.