BIRTH OF THE PERIODIC TABLE
The Ultimate Cheat Sheet of the Universe
| periodic_table.docx |
Imagine playing a card game for three days straight without sleeping. Sounds intense? Well, that’s exactly what Dmitri Mendeleev did in 1869. Back then, scientists only knew about 63 elements, and they were having a hard time organizing them. They tried sorting them by weight or by how they acted (properties), but nothing quite fit.
Mendeleev was obsessed. He wrote the properties of every single element on cards and played "Chemical Solitaire," trying to find a pattern. Finally, exhausted, he crashed. While he slept, he had a dream (there comes the dream again) where all the elements fell perfectly into place in a grid. He woke up and scribbled it down immediately.
Mendeleev was obsessed. He wrote the properties of every single element on cards and played "Chemical Solitaire," trying to find a pattern. Finally, exhausted, he crashed. While he slept, he had a dream (there comes the dream again) where all the elements fell perfectly into place in a grid. He woke up and scribbled it down immediately.
The "Psychic" Move
|
The "Psychic" Move: Mendeleev’s table was cool, but his real genius was what he didn't put in. He saw that the pattern had holes, so he left gaps in the table.
|
He boldly predicted that new elements (like Gallium and Germanium) would be discovered to fill those spots—and he was right! That is why we call him the Father of Chemistry.
Mendeleev's Backstory
- Born in 1834, he was likely the youngest of 14 kids!
- After his dad went blind and lost his job, his mom restarted a glass factory to support the family. Then, the factory burned down, and his dad passed away.
- Determined to get Dmitri an education, his mom walked with him almost 1,000 miles from Siberia to Moscow. When he didn't get in there, they kept walking to St. Petersburg. He eventually got into college, but his mom died shortly after, leaving him an orphan who went on to change science forever.
So, What the Heck Is It?
The Periodic Table isn't just a random, colourful list that science teachers purchase to make their room look official (ahem). Everything in it fits like a puzzle, and makes incredible sense.
The table is organized in:
The table is organized in:
- 7 Periods: These are the rows (left to right).
- 18 Groups: These are the columns (up and down).
What you will notice on periods is, the atoms are organized in crescent order of protons, from left to right. Hydrogen (1 proton) may look lonely up there, but if you go straight to the other side, you will see Helium (2 protons). The next period starts with 3, and so on and so forth.
The reason why there is that gap in the middle is because of the groups. As it turns out, elements that fall into certain groups act the same way molecularly speaking; to the point that you can even predict how an element will behave based on their location, even if you don't know what it is!
The reason being, they have the same number of electrons on their valence layer. So, if you look at Fluorine, it has 9 protons, and 7 electrons in the valence layer; Chlorine, which has 17 protons, also has 7 electrons in their valence layer!
The other number near the symbol (usually underneath or to one side)is the mass of the atom. The table considers a proton and a neutron mass equal to 1. The rest of the mass is made of electrons, but since electrons are super light, they usually only add a small fraction of weight to the atom.
If you subtract the number of protons from the mass of the atom, then you get the mass of the neutrons. Knowing that protons and neutrons should have a mass of 1, this also gives you the number of neutrons in an atom!
For example, let's look at lead.
DO NOT fall into the mistake of thinking that the number of protons equals the number of neutrons! Each atom will have as many neutrons as it needs to keep the atom's positive parts separate.
|
Lead has 82 protons.
The mass of protons is 82. 207.20 - 82 = 125.20 This means the atom has 125 neutrons. |
Hydrogen: A Special Dude!
Hydrogen is usually placed on the left side of the periodic table. However, Hydrogen is a non-metal, not a metal. The lightest element, hydrogen, is a colourless, odourless, tasteless, and highly flammable gas. Hydrogen makes up over 90 percent of the atoms in the whole universe! On Earth, most of it is combined with Oxygen as part of the compound water.
The 10 Families
Look for the colours!!!
|
Alkali Metals: Soft, shiny and metallic solids. These guys are dramatic. They react violently with water (fizzing, popping, creating hydrogen gas). As you go down the group, they get even more reactive and dangerous. They have a single valence electron, which they readily lose to form a +1 ion.
|
Hydrogen is on top, but it is not a part of this group! Why?
|
Alkaline Earth Metals: These are also very metallic and good conductors of electricity, but are less reactive than the alkali metals. They have two valence electrons and lose them to form a +2 ion.
|
|
Transition Metals: These are metallic elements found in the center of the periodic table.
|
They are good conductors of heat and electricity, have high melting points, and can form variable oxidation states and complex ions.
|
Basic Metals: These are common, abundant, and relatively inexpensive metals used in industry, as opposed to precious metals. They usually can corrode and oxidize easier than other metals!
|
|
Semi-Metals: Also known as the metalloid family, this is a group of elements with properties between those of metals and nonmetals. They look shiny like metals, but are brittle, like non-metals.
|
They are semi-conductors, which means they can transmit electricity only in certain circumstances.
|
Non-Metals: These lack the typical properties of metals, such as metallic luster, malleability, or ductility. They generally have high electronegativity and tend to gain or share electrons in chemical reactions, often forming covalent bonds.
|
|
Halogens: The name "halogen" means "salt-former" because they readily react with metals to produce salts, such as common table salt (sodium chloride). They are one of the most reactive -- because they have 7 electrons and only need 1 to be stable!
|
They exist in all three states of matter at room temperature (gas, liquid, and solid).
|
Noble Gases: These elements are "noble" because they don't like to mix with the commoners. They are unreactive. For instance, Neon (lights) and Argon. Since they don't react, they are always gases. Why do you think that is? Let's take a look at Argon and see if we can figure out.
|
|
Lanthanides: These elements are soft, silvery-white, and good conductors of electricity; they are known for their magnetic properties and use in electronics. The coolest thing is that many of them are fluorescent under UV light!
Actinides: These are noted for being radioactive and are essential to nuclear energy applications. They can also spontaneously combust in air (how fuuun).
Remember Ions?
Let's see how to tell if a bond is ionic or covalent!
It's all about what families the elements occupy (and logic!)
It's all about what families the elements occupy (and logic!)
A Cool Trick
The method above is so clean and simple.
And you can think of it in colours! :)
If a molecule mixes yellow and red on the table below, it's an ionic bond; if it's only yellow, it's covalent!
And you can think of it in colours! :)
If a molecule mixes yellow and red on the table below, it's an ionic bond; if it's only yellow, it's covalent!
Diatomic Elements
In nature, some elements are so unstable alone, they group together with another atom of the same kind; they are always in twos.
The seven diatomic elements are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine, and Iodine.
These elements exist naturally as molecules composed of two atoms bonded together. A helpful mnemonic to remember them is "Have No Fear Of Ice Cold Beer".
The seven diatomic elements are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine, and Iodine.
These elements exist naturally as molecules composed of two atoms bonded together. A helpful mnemonic to remember them is "Have No Fear Of Ice Cold Beer".
Endangered Elements??
Of the 118 elements that make up everything—from the compounds in a chemist’s arsenal to consumer products on the shelf—44 will face supply limitations in the coming years. These critical elements include rare earth elements, precious metals, and even some that are essential to life.
Endangered elements in the chemical enterprise face critical supply risks, making sustainable management of their extraction, use, reuse and dispersion essential. In addition to the environmental cost of extracting and processing endangered elements, there is, for some of these materials, an additional human cost of conflict minerals mined to finance armed disputes. Research into more abundant alternatives, more efficient uses, recycling and recovery will help mitigate risks and move industry towards sustainable supply chains.
Endangered elements in the chemical enterprise face critical supply risks, making sustainable management of their extraction, use, reuse and dispersion essential. In addition to the environmental cost of extracting and processing endangered elements, there is, for some of these materials, an additional human cost of conflict minerals mined to finance armed disputes. Research into more abundant alternatives, more efficient uses, recycling and recovery will help mitigate risks and move industry towards sustainable supply chains.
Looking at Phosphate
Phosphorus is essential for life and has no substitute. It is the second most abundant mineral in the human body, VITAL for teeth, bones, DNA and energy transfer.
Phosphate rock is a finite resource that was formed from the mineralization of dead sea creatures over tens of millions of years and then lifted to the land via tectonic uplift.
It is one of the three key ingredients in fertilizer; 90% of phosphorous is used for food production, but 80% of phosphorus is lost or wasted in the supply chain from mine, to field, to fork. Most phosphorus is ultimately lost to water bodies via agricultural runoff and waste water.
The thing is, we need to use phosphorous in fertilizer to ensure the plants grow healthy. Phosphorus is present in soils, to different degrees, depending on the bedrock. However, most applied phosphorus comes from phosphate rock mining, but in farming, people use the same soil over and over. This depletes the natural minerals of the soil, so people have to add it back. But this has to be done in a very careful way, so that we stop wasting this resource, and damaging the environment...... because all the phosphorous that gets washed off ends in our bodies of water, and excess phosphorus in water causes algal blooms and eutrophication.
Phosphate rock is a finite resource that was formed from the mineralization of dead sea creatures over tens of millions of years and then lifted to the land via tectonic uplift.
It is one of the three key ingredients in fertilizer; 90% of phosphorous is used for food production, but 80% of phosphorus is lost or wasted in the supply chain from mine, to field, to fork. Most phosphorus is ultimately lost to water bodies via agricultural runoff and waste water.
The thing is, we need to use phosphorous in fertilizer to ensure the plants grow healthy. Phosphorus is present in soils, to different degrees, depending on the bedrock. However, most applied phosphorus comes from phosphate rock mining, but in farming, people use the same soil over and over. This depletes the natural minerals of the soil, so people have to add it back. But this has to be done in a very careful way, so that we stop wasting this resource, and damaging the environment...... because all the phosphorous that gets washed off ends in our bodies of water, and excess phosphorus in water causes algal blooms and eutrophication.
Eutrophication:
Just the meat, no bun
- Periodic tables hold elements organized by number of protons, from left to right.
- Columns are called groups. Elements on the same group will behave atomically the same way, as they have the same number of electrons on their valence layer.
- There are seven diatomic elements. They are always present in nature as a twin atom.
- There are 10 families of elements. They can be found closeby on the periodic table. Families have the same chemical and physical characteristics (colour, ductibility, conductibility, etc).
- YES you need to know about each family, go up and check it out!!!
- Columns are called groups. Elements on the same group will behave atomically the same way, as they have the same number of electrons on their valence layer.
- There are seven diatomic elements. They are always present in nature as a twin atom.
- There are 10 families of elements. They can be found closeby on the periodic table. Families have the same chemical and physical characteristics (colour, ductibility, conductibility, etc).
- YES you need to know about each family, go up and check it out!!!
