Learn the name and symbol for elements 1-20 (quiz on Friday) Read off the names of the 20 and symbols.
Dalton’s atomic theory 4 parts to describing an Atom. Dalton was not correct but “Close Enough to Count!”
Re: The Nuke Thread Dalton’s atomic theory1. Elements are composed of submicroscopic atoms and are indivisible.Smallest part of an element is an atom.
If you divide an atom smaller than an atom, it stops acting like the element and loses it’s elemental properties.So Dalton was,“Close enough to count”.
Dalton’s atomic theory(Not correct, should be same isotope)2. Atoms of the same element are identical
Should be:Atoms of the same element have the same chemical properties and are therefore almost identical.ORAtoms of the same isotope are identical. So he was,“Close enough to count”.
3. Atoms can combine with one another in simple whole-number ratios to form compounds(Means water is always 2 H and 1 O.) Compound means “Fixed Ratio” like H20, not like salt water, a mixture of NaCl and H20.
4. Chemical reactions occur when atoms are separated, joined, or rearranged. Atoms are never changed into a different element. Who was the king of alchemy? Midas and his golden touch.
building blocks of atoms: electrons, protons, neutrons WOD’s at end of this section.
Electrons (e-)are the smallest negative charge mass 0.0005 AMU (count as 0 AMU)2000 e- = size of 1 p+
Electrons (e-)are the smallest negative charge Thank you for TV!!!! Screen is RGB dots. 1 dot is a pixel. Purple = magnetic charge
Protons and Neutrons are found in the tiny nucleus. Electrons surround the nucleus in a vast cloud. The electron cloud is many times bigger than the nucleus.
If the nucleus were the size of a marble, then the electron cloud would be the size of What? Guess.
If the nucleus were the size of a marble and placed on the middle of the 50 yard line, then the atom or electron cloud would be the size of Chief’s Arrowhead Stadium
Break up a 2nd marble into 2000 pieces. For Carbon 12, pick 6 of those pieces and scatter around Arrowhead. Those 6 are the e- cloud.
Nucleus = marble and on the middle of the 50 yard line. Electron cloud = size of Chief’s Arrowhead Stadium.Then WHAT IS MOST of an Atom made up of????
In an atom, what isBIG Protons and NeutronsSMALL Electrons (and everything else???)
WOD Definitions:Atom’s Parts: Proton, Neutron, ElectronAtomic Mass Unit: AMU, Mass of 1 proton and standard mass measurement.Proton: positive charge, in nucleus, p+,mass 1.0 AMUNeutron: neutral charge, in nucleus, no,mass 1.0 AMU (think as size = p+) Close enough to count!Electron: negative charge, orbitals (orbit), e-, very small so count as 0 AMU.Nucleus: Center of an atom = p+ and no.
Atomic number = protonsWhole number. It is number of protons in the nucleus of that element He = Atomic number of 2
Atomic mass = proton + neutrons.total number of protons and neutrons in the nucleus He = Atomic mass of 4
Carbon 14Name followed by atomic mass.C 14: Name is Carbon which means 6 protons and 6 electrons. 14 means protons + neutrons = 14, i.e., 8 neutrons.What is different about Carbon 12?
Carbon 12Name followed by atomic mass.C 12: Name is Carbon which means 6 protons and 6 electrons. 12 means protons + neutrons = 12, i.e., 6 neutrons.It has 2 less neutrons than Carbon 14?
“Write Notes Here” from previous page.Write the following in the correct places on your HW. Use some twice. p+, e-, no, = At#= p+ + no = p+ (two places)= Mass - At#Pos, Neutral, Neg. Big Small Nucleus Orbits 1 AMU 0 AMU
Isotopes – different numbers of neutrons. Same number of protons, same element. # of Protons or Atomic Number determines the chemical behavior of an element. So Isotopes of the same element behave the same way Chemically. Very hard to separate isotopes. 1 or 2 Pencils in hand of a sprinter.
Isotopes – different numbers of neutrons. Same number of protons, same element, Carbon 12, Carbon 13, Carbon 14 What is H3 or C14 known for?
Average atomic mass – average mass of all isotopes found in nature of an element (shown on P-table)
calculating average atomic mass-number of stable isotopes of that element -mass of each isotope -natural percent abundance of each isotopeFormula (mass × decimal abundance) then add togetherDon’t worry if you don’t follow, we will show several examples.
Fictional element X The above two isotopes are found. What is the average atomic mass of this fictional element X?
The above two isotopes are found. What is the average atomic mass of this fictional element X? 14amu (.7200) + 15amu (.2800)=14.28 amu14.28 would be the number on the periodic table
14.28 would be the number on the periodic tableNOTES: 1.) 14.28 does not end in .000, so it must have isotopes.2.) 14.28 is closest to 14, so 14 is the most common isotope in nature.3.) .28 is bigger than .000, so the other isotopes are most often 1 bigger than 14. (Approximation, not a law)
A chemical is found to have three isotopes, what is the average atomic mass of this element?54amu 72.00% 55amu 25.00%57amu 3.000%
A chemical is found to have three isotopes, what is the average atomic mass of this element?54amu 72.00% 55amu 25.00%57amu 3.000%54 amu x .7200 + 55amu x .2500 + 57amu x .03000 =38.88amu + 13.75 amu + 1.71amu = 54.34 amu