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Atomic Fundamentals 2

Added Sep 01, 2014 •

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our title today is atomic fundamentals here is a projection of periodic table that I gave you  class today on this periodic table are listed the 92 planets and the rest which are human made purchase very small  okay so what distinguishes one element from another what did all these elements that's why we're going to talk about today  okay so again you guys you need to write down every single thing that is written here plus anything extra that you feel you will need  okay so ugly most of the all matter is made of atoms  now course is anything that has mass and volume  there are limited number of types of atoms that naturally occur and call me music  composition of an atom  is that at the center of an atom we called after nucleus it's made up of protons and neutrons  and rounding the nucleus  are layers of orbiting electrons okay one thing to keep in mind electrons  valence electrons that means outer the outermost shell of electrons they can be removed protons and neutrons they are never remove added or removed unless we're talking about some sort of nuclear reaction but electrons can I just learning how to use cook now what holds an atom together what holds the electrons orbiting around captain of the electron  the nucleus is the basis of the structure of the atom so as we'll see you in a moment electrons party notice I'm sure electrons have a negative charge protons have a positive charge and it is that electrostatic attraction that electrostatic interactions and we sometimes call that well we don't sometimes it is known as a long  interaction and we will talk lots more about Coulomb's law later but basically it is the positive a negative attract one another this really what keeps atoms  together two positively charged nucleus  okay so let's talk about subatomic particles real quickly so subatomic particles and when I say that I'm talking about protons neutrons and electrons of course we can go smaller what we're not studying quantum physics class we're studying chemistry I'm so we don't need to go any further down their Mass relative to one another another charge so wish protons in the nucleus protons  have a relative mass to the other two subatomic I seen one AMU atomic mass unit and its charge is positive one neutrons  they also have a mass of 1 but they are neutral they are not charged and then last but not least  we have the mighty electron the mighty elec God has only one 1800 XL the mass of a proton Neutron  butts look at the magnitude of charge it is opposite but it is equal to the magnitude of charge of a proton so even though its mass is too small he just wants you charge is all right now a couple of things I'm going to throw up and that is  protons and neutrons are held together in the nucleus  by the strong nuclear force as you can imagine protons are all positively charged and keeping those protons in close proximity to one another it's going to take a pretty hefty Force because positives and positives repel so neutrons get in between those protons but overall what holds the nucleus together protons protons neutrons in there is strong we also have something called the weak nuclear force the weak nuclear force is what holds a neutron together neutrons are actually proton and an electron that's what a neutron is and it is so weak nuclear force that holds a proton the other oftentimes in radioactive decay we have neutrons Sante cozy into protons and high energy  okay and last but not least we've got  War Horse electric static Force comic interactions that hold the electron in orbit around the nucleus so if that is in terms of negatives being attracted to cost okay so every element so for talking about gold an element or oxygen oxygen element made up of atoms  that have a common structure so really now what we're going to talk about is what makes gold different from what makes copper different from nitrogen okay it's all about the way that their atoms are composed so we tell that all atoms have protons neutrons and electrons  the atoms of all the elements have a common structure in that they've got a nucleus their proton and they have electrons orbiting around them but what makes one element do bottoms are slick so atomic number is the number of protons an atom of an element and this is really the fingerprint of the atom is the number of protons turned up versus neutrons can vary their numbers of electrons can actually very too we'll talk about that in a few days but  however many protons they have that is really what identifies them as an atom so let's look as periodic table real quickly and and see what I think call Rick so atomic I'm going to I'm going to zoom this in but you should have your periodic table out okay so for instance here is boron boron 5 here is silver silver has tonic number of 47 so again how many protons are in an atom of that element and that never changes if an atom has 47 protons that means it's an atom of silver if an atom has 89 / 18 protons that means it is an atom of actinium okay so the atomic number  tells us number of protons and that is what identifies that's what gives gives that adamant ident as an element  Dallas zoom in a little bit here which shall we see men on let's zoom in on okay so you're sold AU gold hasn't 79 Atlanta news. All atoms of gold have 79 protons golf hey you okay so it's atomic number was it's atomic number 79 so atomic number 79 that means that gold has 79 protons and in a neutral gold atom a neutral gold atom we're not talking about gold on ion button cool gold atom has 79 electrons any neutral app okay so now the question is what about the number of neutrons now for elements number of protons are always the same with their number of neutrons can actually very depending on what ice elements we're looking at sup I'm sure that way up there I'll figure okay so the number of neutrons headed to figure out the number of neutrons found by subtracting the atomic number from the mass number so 4 volts Got7 70 9 protons okay so that's its atomic atomic number so what we need to do is we need to figure out its nest how to do that figure out a mass check so on the periodic table this number right here 196.97 that's Tomic Mass  it's mass number is it's atomic rounded to the nearest whole number 196.97 what will that round to that will round to 197 okay so 197 197 is its mass number okay so that is the atomic mass rounded in order to find the number of neutrons  in a typical  the typical call data we're going take 197  -79 and not is going to give us a 118 and it's typical they will very they so what that is is we think of this as a we name this as ice atoms with equal numbers of protons but different numbers of neutrons are known as I used to toast of an element of course we will you know we'll be doing problems about this tomorrow so we'll get this all cleared up so what is an example of I like to use the example of carbon alright so three isotopes that means that the element carbon its atoms come in three different varieties so we've got carbon  apartment 12  do you have parvinder we have carbon 14 these are all call ICE tubes of carbon  hey what do you think that 6 is  6 atomic  number that we can find those periodic table and what does that strike for us about carbon this tells us how many protons are in a carbon atom and in a neutral carbon atom come here so in each three isotopes of carbon there are 6 protons because proton stop being carpet for the numbers of protons never change in an isotope of a particular element but this 12 13 14 what is that that is the differing Max queso carbon 12 if we subtract 6 from 12 that leaves at 6 so carbon-12 has 6 neutrons carbon 13 13-6 carbon 13 has 7 neutrons  and 6 protons and 6 electrons and Corbin fort age  carbon-14 has 8 News honestly too many neutrons stable and not nucleus and so carbon-14 is  and it was spontaneous alright so we can find these three different kinds of carbon atoms three different isotopes carbon and exist in varying amounts  carbon-12 carbon-13 part 14 but they're all here alright so the last thing we want to talk about here is why the atomic mass a decimal number the carbon has an atomic mass of 12.01 so if I'm going to convert that into a mass on the 12th  but it's not just 12 it's 12.01 is that why aren't these whole numbers  well that's because all elements have various numbers Vice some more than others and so what does this number this is Tomic Mass what is that represents about  it is a weighted average Hudson masses of all the hi.  Alright we'll talk about it weighted-average tomorrow you you can look it up if you don't know what it weighed we'll talk about it tomorrow little bit and then the last thing I want to leave you with where do all these things come from these fundamental building blocks matter  in our solar system all these elements I want you to think about that too and we'll talk about that too

Uploaded by Lisa Graham.

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Atomic Fundamentals 2

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