0:03 Every atom is like a mini universe. But
0:05 deep inside it, three tiny heroes work
0:08 together to decide everything about what
0:10 that atom is, how stable it is, and how
0:13 it behaves. Today, we're zooming in
0:15 inside the atom to meet three of the
0:17 tiniest but powerful particles in the
0:21 universe. The proton, the neutron, and
0:35 [Music]
0:38 Last time we learned that every atom has
0:40 a dense core called the nucleus and
0:42 surrounding it like layers of an onion
0:45 are shells where electrons move around.
0:47 But today we're taking our zoom lens
0:50 even closer to uncover the tiny secrets
0:53 hidden inside. First up, the leader of
0:57 the pack, the proton. Let's start with
1:00 its symbol. Protons are represented as
1:04 P+ because they carry a positive charge.
1:07 That little plus sign is important. They
1:10 have a positive one charge, meaning they
1:12 contribute a positive electrical force
1:15 inside the atom. Before we talk about
1:18 the mass of these tiny particles, let's
1:20 first understand the unit scientists
1:24 used. It's called the atomic mass unit
1:29 or amu for short. 1 amu is about 1.67 *
1:33 10 -27 kg.
1:36 That's incredibly tiny. Even if you had
1:39 a million trillion protons, they would
1:41 still weigh less than a grain of sand.
1:44 Using amu makes it easier to talk about
1:46 mass without getting lost in long
1:50 numbers full of zeros. Protons are
1:52 relatively heavy for a subatomic
1:55 particle. Around one atomic mass unit or
1:58 about 1.6726
2:01 * 10 -27 kg.
2:05 And where we can find protons? Protons
2:07 sit right at the center of the atom in
2:10 the nucleus where they help define the
2:12 identity of the element.
2:15 Protons are like the identity card of an
2:18 atom. They tell us exactly what element
2:21 it is. Think of protons like your ID
2:24 card. They decide who you are. If you
2:28 have one proton, you're hydrogen. Three
2:32 protons, you're lithium. Six, you're
2:36 carbon. If you have 118 protons, you are
2:39 the rare and heavy agoness. Change the
2:41 number of protons and change the element
2:44 completely. Protons are what gives an
2:48 atom its true identity.
2:50 So protons give an atom its identity,
2:53 but there's someone else working quietly
2:56 beside them. Someone just as important,
2:59 but much more neutral. Let's meet the neutron.
3:01 neutron.
3:04 Neutrons are the calm neutral members of
3:06 the atomic family. Neutrons are
3:09 represented by the symbol N0. And that
3:12 little zero, it tells something very
3:15 important. They have no charge. They are
3:18 completely neutral. Which is actually
3:21 where their name comes from. Neutron.
3:23 Neutrons have about the same mass as
3:27 protons. Roughly 1 amu or about 1.6749
3:32 6749 * 10 -27 kg.
3:35 Dust is slightly heavier than a proton.
3:37 Neutrons also live in the nucleus right
3:39 alongside protons.
3:42 Neutrons may not have a charge, but
3:44 don't let that fool you. Their real
3:47 power lies in keeping the atoms core
3:49 from falling apart.
3:51 Let's see how they help maintain
3:54 stability inside the nucleus.
3:57 Inside an atom's nucleus, protons are
4:00 packed closely together. But since they
4:02 all have positive charges, they tend to
4:05 repel each other. If nothing stopped
4:08 this repulsion, the nucleus would become
4:11 unstable and eventually break apart.
4:14 This is where neutrons become important.
4:16 Neutrons have no charge, but they help
4:18 by reducing the repulsion between
4:22 protons. They act like a stabilizer or
4:24 think of them as atomic glue, holding
4:26 the nucleus together and keeping the
4:30 atom stable. Neutrons help keep the atom
4:33 stable, but having too many or too few
4:36 can cause problems. For example, carbon
4:40 12 has six protons and six neutrons.
4:43 It's stable. Carbon 14 also has six
4:47 protons, but eight neutrons. It's still
4:50 carbon, but the extra neutrons make it
4:53 unstable. That's why carbon 14 is radioactive.
4:55 radioactive.
4:57 Neutrons are like glue, but without the
4:59 right amount, the nucleus can fall
5:03 apart. So, yes, neutrons help hold the
5:06 atom together, but they aren't the ones
5:09 making atoms into rock. For that, we
5:10 need something smaller, something
5:13 faster, something charged with energy.
5:16 It's time to meet the electron.
5:19 The electron written as E minus, that
5:22 tiny minus sign, it means big things in
5:25 science. Electrons carry a negative one
5:28 charge. That's the exact opposite of a
5:31 proton. This negative charge is super
5:33 important for electricity and chemical
5:37 bonding. Electrons are extremely light,
5:41 about 1 over 1,836
5:44 the mass of a proton. To put that in
5:47 perspective, imagine a balanced scale.
5:49 On one side, just one proton. On the
5:53 other, it would take about 1,836
5:56 electrons to balance the scale. That's
5:59 how tiny electrons are in terms of mass,
6:03 almost weightless on the atomic scale.
6:05 And unlike protons and neutrons,
6:08 electrons aren't in the nucleus. They
6:11 zoom around it in areas called shells or
6:13 energy levels.
6:16 Electrons are in charge literally of all
6:19 chemical reactions.
6:22 They decide how atoms interact, bond and
6:24 form everything from water molecules to
6:26 living cells.
6:30 Now electrons may be tiny but their role massive.
6:31 massive.
6:33 Let's zoom in how electrons drive
6:36 chemical reactivity.
6:38 Electrons, especially the ones in the
6:41 outermost shell called veence electrons,
6:44 decide how an atom behaves in a chemical
6:47 reaction. Atoms become more stable by
6:49 gaining, losing or sharing these electrons.
6:51 electrons.
6:53 Think of electrons like social connections.
6:54 connections.
6:57 How atoms interact depends on how many
7:00 friends they have or want.
7:02 So yes, electrons bring the excitement
7:04 in chemistry. They're the ones forming
7:07 bonds, breaking them, and starting all
7:10 the action. But here's the thing.
7:12 Electrons don't work alone. To truly
7:14 understand how an atom behaves, you have
7:17 to meet all three players. Because every
7:20 atom's story is a mix of identity,
7:22 stability, and reactivity.
7:25 Protons give the atom its identity. They
7:29 say, "This is who I am." Neutrons add
7:31 stability, keeping the nucleus from
7:33 falling apart.
7:35 and electrons drive reactivity, deciding
7:38 who to bond with and when. Together,
7:40 these three tiny heroes are the reason
7:43 everything exists. From the smallest
7:46 grain of sand to the beating heart of a star.
7:48 star.
7:50 And that's a wrap. This is Learning with
7:53 G. Stay curious, stay inspired, and I'll
7:55 see you in the next lesson. Thank you so
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