Subatomic Particles (Simplified) - Video Tutorials & Practice Problems

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The atom is composed of 3 subatomic particles:neutrons, protons, and electrons.

The Atom & Subatomic Particles

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concept

Subatomic Particles (Simplified) Concept 1

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we've learned that the atom itself is comprised of the nucleus and more importantly, three subatomic particles. Now the three sub atomic particles share key differences and similarities in their masses and charges. Were going to say we're introduced to a new term am you am You is shorthand for atomic mass unit. And it's used to calculate the relative mass of an atom or a subatomic particle. Now we're going to say here that the definitional term of A. M. U. Is that one a.m. U. Equals 1/12 the mass of a carbon atom. All right, so this is again the official definition of an A. M. You. But what you need to realize here is that one a.m. U. Is equal to one dalton, which is abbreviated D. A. It's named after john dalton. John dalton represents one of the fathers of chemistry. And the more chemistry you learn, you learn that there's quite a few fathers and mothers of chemistry. They helped with important discoveries ranging from a subatomic particles to their charges to some types of radiation and radio activity. Now what's most important here is remember what's in the Prebble box you need to commit to memory and that's one a.m. U. Is equal to 1.66 times 10 to the negative 27 kg. So this conversion factor will allow you to go between am you and kilograms. You'll be able to inter convert between the two units. Yeah.

In terms of size, neutrons are the largest, protons are slightly smaller, and the electrons are the smallest.

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Subatomic Particles (Simplified) Concept 2

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So remember we have three subatomic particles when it comes to the atom itself. So here we arrange them in neutron proton and electron. In terms of order In terms of these three subatomic particles, we have information on their actual masses, their relative masses, and then their relative charges. So the neutrons, they way the most out of the three sub atomic particles. Their actual mass is 1.67493 times 10 to the -27 kg. Protons are slightly lighter there 1.67262 times 10 to the negative 27 kg. So their masses are pretty close to one another. They themselves are much heavier than the electrons. The electrons are .0009, 1 times 10 to the -27. So what does this tell us? Well, we know that the nucleus is comprised of protons and neutrons and the nucleus itself is incredibly small. But a vast majority of the mass of an atom is found within the nucleus. So it's important to understand that the nucleus is very small but very dense. A majority of the mass of the atom is found there. And if the result of the neutrons and protons masses together, now we have their actual masses. We also have their relative masses, which you should also remember in terms of A. M. You okay, now it's important to understand the trends. Neutrons are the heaviest electrons are the lightest these exact numbers. If you're going to deal with the question, having to relate them, they'll give it to in some form within the question. So don't remember. You don't have to memorize the actual number. Remember what's in purple boxes, what you need to commit to memory. So the relative mass of a neutron is 1.00866 a. m. U. For proton, it's slightly less in mask, so it's 1.007-7 am you. And then remember electrons way the least. They're only .00055 a. m. U. Now they're charges. We know that neutrons are neutral. So their relative charges zero Protons are positive. Their relative charge for each proton is plus one, electrons are negative, so there -1. All right. So, just remember neutrons are neutral and protons and electrons have the exact opposite signs for their charges. So here this represents the most important information need to know in terms of masses and relative charge for your three subatomic particles.

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example

Subatomic Particles (Simplified) Example 1

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So in this example question. It says, Oz me, Um, one of the densest elements on earth has an actual mass of 190.23 g according to the table above what is its value in terms of atomic mass units? All right, so if we take a look here, all our answers are given indulgence. Remember, Adult in is the same thing as an atomic mass unit. We're gonna start out with this given amount, So this is our given amount, and it is our responsibility to get to the end amount. So we need to get to this end. Amount now are given amount is 1 90 to 3 g, and we have to get to our end amount in Dalton's, which is the same thing as I am you now. In order to go from are given amount, tow our end amount, we have to utilize conversion factors. Now, the conversion factor we're gonna use here our first conversion factors Conversion factor one, we're first going to do a metric prefix conversion. We're gonna change grams to kilograms. We want to get rid of grams, so grams go here on the bottom kilograms go on top. Remember the coefficient of one goals on the side with the metric prefix meaning 1 kg is 10 to the three. Now that grams are on opposite levels, they cancel out, we'll have kilograms at the end. We have to change the kilograms because now we're going to say for conversion factor to our metric prefix above says that 1.66 times 10 to the negative kg is equal to 1 a.m. U. Remember an AM you and adult in are the same thing. So now our kilogram numbers cancel out, and we'll get our answer here as Dalton's can. So what's gonna be here? It's 1 90.23 divided by 10. divided by 1.6 times 10 to the negative. 27. Remember, something is written in scientific notation. Tow. Avoid any errors within your calculator. You should put it in parentheses. If you do this correctly, what you'll get initially. Well, what you get at the end is 1.15 times 10 to the 26 Dalton's or am. You remember they're interchangeable with one another. So if you look at our choices here. Which one matches up with that value? That would be option A. So here we're talking about conversion of grams 2 a.m. Your Dalton's. This is called dimensional analysis. We start out with are given amount. We have to get to our end amount and to get there, we utilize conversion factors here. We had to employ metric prefix conversion with conversion factor one and then use the metric used the conversion factor listed above for conversion. Factor to that takes us from kilograms to Dalton's or am you? So if you're a little bit rusty in terms of this, make sure you take a look at our videos on dimensional analysis, because this is the basic set up for any dimension analysis type of question.

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Problem

Problem

According to the table above, how many electrons are needed to have a combined mass of 1.0465 x 10^{-25} kg?

A

2.1028 x 10^{13}

B

1.1500 x 10^{5}

C

8.8192 x 10^{25}

D

3.2235 x 10^{22}

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Problem

Problem

How many atoms are contained in 0.230 g of sodium, Na? The mass of one sodium atom is 23.99 amu.

A

7.197 x 10^{11}

B

4.182 x 10^{3}

C

5.775 x 10^{21}

D

9.181 x 10^{41}

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