1 Watch the video and put the words into the gaps in the text.
Hello, friends! I am an atom, yes an atom. Can you see me? Oh, yes. I
know you can see me on your screen, but I am just an imaginary 1___ of an
atom. Real atoms are too tiny. You can only see them under a very special 2____.
Actually, this big microscope can be called a 3____. Okay, now you know that
we are so tiny that we can only be seen with machines.
Now, I have a question for you. Do you know the meaning of your name?
Very good if you know it. If you don’t know, ask your parents. But I also
know the meaning of my 4____; it means “that which can’t be cut”, “that which
is uncuttable”. Actually it’s a Greek word which means it is 5_____, which
means it can’t be divided further or can’t be cut further. Let me show you
something; let me ask this man to cut the apple in his hand in half. Now, do
it again, please, do it again, keep doing it until you can’t 6____ it any
further. Yes, this is the smallest part which you can’t cut any further, but
it can also be cut under 7____ machine. So, if you get a part so small which
can’t be divided further, it is called indivisible. It can’t be cut further,
it is uncuttable, it is an atom.
Let me tell you a secret.
Everything is made up of atoms: you, this water, this table, this blackboard,
this pen, these fruits. Everything, everything is made up of atoms. Oh,
you’re right too. Everything is made of 8____, but all molecules are made of
atoms. Confused? Go to the blackboard and write any sentence. Good. Now, this
is a whole sentence. Now, 9____ all the words in this sense, now let’s take a
word, and circle all the letters of ‘are’ with some other color. Very good.
You see, this sentence is made up of 10____, but words are made up of
letters, so 11____ are the smallest units of a sentence. Similarly everything
is made up of molecules, but molecules are made up of atoms. So atoms are the
smallest unit of everything.
Look at this. See, water is made up of water molecules, but water is
made up of atoms. There are two atoms of 12____ and one atom of 13____ in
each water molecule. So when atoms join together, they form a molecule, and
when molecules 14____ together they form a thing. So, now you understand. So,
now, friends, I would show my body. Yes, I would show different parts of my
body. In the centre of an atom there is the 15____, it is made up of even
smaller parts. These are called protons and 16____. Each of these protons
carries a 17____ electrical 18____. The neutrons are equally as heavy as
protons, but don’t carry any electrical charge. So, the nucleus of an atom is
positively charged due to protons. Now, electrons are outside the nucleus,
they’re 19____ around the nucleus. The electrons carry a 20____ charge. The
total negative charge of electrons is equal to the positive charge up the
nucleus. So, in total an atom is neutral. The positive charge of the protons
is neutralized by the negative charge of the electrons. So, it’s like +1 is 21_____
by -1 and overall charge of an atom becomes 0. The electrons are moving
outside the nucleus at a very high speed. Can they run away from the 22____?
No, they can’t run away. Every atom has the same number of protons,
electrons, and neutrons. So there is
an attraction between equally strong negative and positive charges. Due to
this 23_____ electrons can’t run away as positively charged protons keep them
pulled towards them. Hope this is all cleared on the view. Otherwise you can
always go back and see it again.
Now, let me explain how we, atoms, bond together to form a molecule.
It’s just like the letters getting together to form a word. Electrons keep
moving in 24____ outside the nucleus. Each shell contains a fixed number of
electrons. The first shell can have two electrons, and the second can have
eight electrons, the third can hold eighteen, and the fourth can hold up to
thirty two electrons. The atoms in the 25____ shell of an atom are called 26____
electrons and the outermost shell is called the valence shell. Atoms bond
with other atoms to form a 27____ with these valence electrons in the valence
shell. Remember one thing: atoms always keep trying to fill their shells.
Take for example and oxygen atom. In its second shell it can hold up to eight
electrons, but the oxygen atom only has six electrons in its second shell. So
it is always looking for more electrons to 28____ its shell. Now, here is a
hydrogen atom. It only has one electron in its outer shell, but it can 29___
two electrons in its shell. So it is also 30____ more electrons. So the
oxygen atom bonds with two hydrogen atoms to fill its valence shell by
sharing one electron from each hydrogen atom. In this way the hydrogen atoms 31____
is also fulfilled as they can also fill their shells to their 32____ of two
electrons in their valence shells. By combining together they become water
molecules. So, friends, now you understand us. I am part of you, so learn us
well by watching this video again and again.
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microscope
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machine
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picture
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indivisible
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cut
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microscopic
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name
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letters
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circle
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molecules
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words
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attraction
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nucleus
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oxygen
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positive
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negative
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nucleus
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orbiting
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neutrons
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hydrogen
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charge
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neutralized
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join
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molecule
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outermost
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capacity
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hold
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requirement
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fill
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valence
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shells
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looking for
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2 Vocabulary focus. Study the words and word combinations, practise their translation, spelling. Check your knowledge
in the test. Play vocabulary game and set your own vocabulary game record.
3 Mark the following statements as True or False.
1 Atoms are too tiny and people cannot see them without microscopes.
2 Atoms are made of molecules.
3 Protons carry negative charge.
4 Every atom is always charged.
5 Each shell contains a fixed number of electrons.
6 The first shell of an atom can hold up to three electrons.
4 Answer the Questions.
1 What does the word “atom” mean?
2 What do atoms form when they are joined together?
3 What parts does the atom consist of?
4 Can electrons run away from the nucleus? Why is it possible or
impossible?
5 What is shell?
6 What do atoms always try to do?
7 What is valence?