- [Instructor] Think about all the thousands of books
and poems and articles and dictionaries and encyclopedias
and textbooks and so much more.
All those English writings are fundamentally made of what?
26 letters
and yeah, some spaces, but that's it.
These 26 letters forms the building block
of almost every single thing,
all the uncountable words and sentences that you can make.
Now, guess what?
Turns out our nature is similar.
Almost everything that you can touch and taste
and smell and feel around you,
from the germs to microbes
to stuff like cats and dogs
to oceans and mountains and even planets and stars.
Turns out all of these are also made
from just a few building blocks, about a hundred of them.
Each square over here represents a building block,
and we'll talk a little bit
about how we arrange them and stuff,
but these building blocks are called the elements,
and that's what we're gonna talk about in this video.
So let's do that.
First of all, these elements,
the building blocks are also called pure substances.
And like I said earlier,
they make up almost all the matter around us.
For example, if you consider water,
it's made of two kinds of elements: hydrogen and oxygen.
And consider any living being like yourself,
that you are mostly made of six elements:
oxygen, carbon, hydrogen,
nitrogen, calcium and phosphorus.
I mean, there are other elements,
but these mostly make it up.
And just to give you another example,
if you consider any rock,
and they're mostly made of five elements:
silicon, oxygen, aluminium, magnesium, and iron.
Don't worry about remembering the names
of these elements for now.
What's important, and I keep repeating
because it's so important,
is that almost all the matter in the universe is made
from these elements.
So to study matter, we need to study these elements.
So let's do that.
We arrange these elements in this particular form,
and we call this the periodic table.
It might seem daunting at first, but let's look at it, okay?
So first of all, you can see
that each element gets a square and a number.
So element number one is hydrogen.
Element number two is over here, helium.
Element number three is lithium.
Element number four is beryllium, and so on and so forth.
What we wanna notice over here is
that each element has a symbol, kind of an abbreviation.
Now, for some elements,
that's basically the first letter of the word.
H for hydrogen,
B for boron,
C for carbon,
N for nitrogen, and so on and so forth.
And notice we always use capital letters.
But what about other elements which start
with the same letter, for example, helium?
How do we ensure we don't confuse it with hydrogen?
Well, we use first two letters, so He.
Similarly for calcium,
to make sure we don't confuse it with carbon,
we use the first two letters, Ca and so on and so forth.
But what's important again over here is
to notice how we write it.
When we have the two letters,
the first letter is capital over here,
the second letter is small.
So we'll never write helium this way where both are capital
and we'll never write this way where both are small.
We'll always write as first letter capital,
second letter small, and that's always the case.
Alright, these make sense, but what about sodium?
Sodium is Na, what's going on over here?
And then there's more such stuff.
So for example, gold is Au.
Tungsten, which is used in the filament of our bulbs, is W?
And lead is Pb.
What's going on over here?
Well, humanity has known about these elements
for a long time now,
and some of these symbols are taken from the old names
from different languages like Greek, Latin,
Arabic, German, and so on.
For example, Na stands for natrium,
Latin word for sodium.
Au comes from aurum.
Pb comes from plumbum, the Latin word for lead.
Fun fact earlier pipes
in the Roman Empire were made from lead,
and therefore people who used
to fix those pipes are called plumbers,
and the name is stuck today.
And W comes from the German, wolfram.
Now again, you might be thinking,
"Oh my God, how am I supposed to remember all of this?"
Don't worry, we don't have to do that.
As we start talking about some of the common elements
over and over again,
we'll start familiarizing ourselves with them.
So don't worry about it.
So in summary, all the matter that you see,
almost everything in the universe,
is made of a few, about a hundred elements,
which we also call the pure substances.
They're arranged this way
in what we call the periodic table.
And just like how learning the English language
is basically figuring out
how we can combine these different letters
to form very interesting words and sentences.
The trick to learning about matter
is learning how we can combine these different elements
to form interesting new things.
It's kind of like legos,
the plastic building blocks we used to play with before.
Well, imagine we had a hundred different
kinds of legos with us.
Then by combining them in different combinations,
you can build up almost anything you want.
And now you can imagine some
of these lego structures are like mountains
and others are like cats.
And we can build whatever we want.
We can let our imagination lose over here,
which is pretty awesome.
But if you break them all down into their basic pieces,
you get back your elements.