Bellringer: Number you paper 1-5 and see if you can determine what these magnified photos are! 1. 2. 3. 4. 5. The Answers: The Structure of the Atom and the Periodic Table Chapters 4, 5, 10 Atomic Theories- Modern
Atom The smallest particle of an element that retains the properties of the element end Structure of the Atom Atoms are made up of 3 particles Protons, Electrons, and Neutrons Called subatomic particles
You must identify them by mass, charge, and location end Structure of the Atom The Nucleus Small, dense region in the center of an atom Contains:
Protons and Neutrons All of an atoms positive charge Almost all of an atoms mass. end Structure of the Atom Proton (p+) Charge of +1
Found inside the nucleus Mass of 1 The number of protons defines an element Change the # of protons and you get a different element end Structure of the Atom Neutron (n0) No charge Found inside the nucleus Mass of 1 (same as a proton) The number of neutrons controls the isotope Change the # of neutrons and you get different isotopes end
Structure of the Atom Electron (e-) Charge of -1 Found outside the nucleus Almost no mass (1/1840 = 0.000543) The number of electrons controls the electrical charge Change the # of electrons and you get a charge (an ion)
end Review Particle Symbol Location Relative Mass Relative Electrical Charge Change in Number
Electron e- Outside the Nucleus 1/1840 -1 Ions Basically = 0 Proton
p+ Nucleus 1 +1 Elements Neutron n0 Nucleus 1
0 Isotopes end Structure of the Atom Atomic The number of protons Number
This defines each element Equals the number of electrons in a neutral atom Atomic Number end Structure of the Atom Mass Number The relative mass of each atom Mass # = (Atomic #) + (# of neutrons) # of protons
end Isotopes Isotopes Atoms of the same element With different numbers of neutrons Which means different mass numbers All elements have isotopes Elements occur naturally as a mixture of isotopes
end Structure of the Atom Atomic Mass Weighted average mass for all isotopes of each element NOT the same as the Mass Number Atomic Mass end Structure of the Atom Atomic Symbols 1 or 2 letters The 1st letter is ALWAYS Capitalized, and the 2nd is ALWAYS Lowercase Make sure to write your letters correctly!!!!!
The elements name is just below the symbol Atomic Symbol Elements Name end Structure of the Atom Writing Atomic Symbols Since all elements have isotopes, scientists must indicate the isotope when they write symbols You need to recognize the isotope from the symbol Carbon- 12 Name and Mass Number Mass Number
C- 12 Symbol and Mass Number Atomic Number end 12 6 C Symbol Bellringer: 1. This element has 30 protons and 30 neutrons. What element is it?
2. How many protons, neutrons, and electrons does Bromine-80 have? 3. What is a ghosts favorite fruit? 4. STOTD Atomic Theories- Modern Bohr Model (Solar System Model) Placed electrons into energy levels Electrons change energy levels by gaining or losing energy Electrons cannot be between levels
Electrons can move more than 1 level at a time end Atomic Theories- Modern In the Bohr Model: Protons and Neutrons form a nucleus Electrons are placed in rings around the nucleus Each energy level can only hold a certain number of electrons Energy Level # of electrons 1 2 3 4
2 8 18 32 end 2n Atomic Theories- Modern Lets draw Li-6 Lets draw H-1 p=3 p=1 n=3
n=0 e=3 e=1 Lets draw He-4 p=2 n=2 e=2 Lets draw Na-22 p = 11 n = 11 e = 11 end
Bellringer: ***You need a Periodic Table for today! 1.Describe the nucleus of an atom. 2.How many protons, neutrons, and electrons does Mg-25 have? 3.What is the mass number, atomic number, and average atomic mass for Mg-25? 4.Write Mg-25 in nuclear notation. 5.Safety Tip of the Day Structure of the Atom Name Symbol Protons Neutrons Electrons Atomic Mass Number Number
Carbon12 C 13 6 15 45 44 34 36 15 end
ELEMENT QUIZ FLASH CARDS!! Atomic Theories- Modern Electrons want to be in the lowest energy level possible Ground state All electrons are in the lowest possible energy levels The most stable Excited
state At least 1 electron is not in the lowest possible energy level end Atomic Theories- Modern Bohr's model was good, but it had problems We cannot know the exact location of electrons Electron
Cloud Model Some fancy math allowed us to figure out an area where the electrons will be 95% of the time This area is known as an Orbital Each orbital can only hold 2 electrons end Bellringer: 1. Complete the following for Boron- 11: a) b) c) d) e)
f) Mass Number Atomic Number Number of Protons Number of Neutrons Number of Electrons Write it in Nuclear Notation 2. Draw the Bohr model for the atom. 3. STOTD Bellringer: Can you unscramble all the words below? Hint: They all start with the letter B. CAERTBIA 1. I can make you sick.
LOBOD 2. I flow through your body. OBLIOGSIT 3. I study living things. SEBA 4. I have a pH over 7. NOBES 5. We support your body. Radioactivity Chapter 10
Nuclear Decay Radioisotopes Atoms of an element with an unstable nucleus When the nucleus breaks down (decays): The atom changes into a different element And, Radiation is Released end
Radiation: Charged Particles and Energy Types of Nuclear Radiation Alpha () Particle Given off during alpha decay Positively charged Made up of 2 protons and 2 neutrons 238
92 Its the nucleus of helium (He+2)!!! U 234 90 4 2 Th He 238 92 U 234
90Th Alpha Particle end Least penetrating type of nuclear radiation Can be stopped by a sheet of paper or clothing Types of Nuclear Radiation Beta () Particle
Given off during Beta decay A Beta Particle is An Electron!!! 234 90 U 234 91 Pa 0 1 e 234 90
U 234 91 Pa Beta Particle More penetrating than alpha particles Can be stopped by a thin sheet of metal end aluminum foil Types of Nuclear Radiation
Gamma () Ray Produced during Gamma decay High Energy Light No particles 234 90 Th
end 234 91 Pa 0 1 e Most penetrating type of radiation Stopped by several meters of lead or concrete Types of Nuclear Radiation
end Types of Nuclear Radiation Radiation Type Symbol Alpha Particle or Beta Particle or Gamma Ray
end 4 Charge Mass (amu) He +2 4 e
-1 1/1836 0 0 2 0 -1 Nuclear Equations Shows the break down of a radioactive element Includes the atomic number and the mass number
The total mass number and atomic number must be equal on each side of the equation Remember Nuclear Notation?? Nuclear Reactions Nuclear Equations Shows the transmutation Total Mass Number and Total Atomic Number must be equal on each side of the equation 94 41 0 1 Nb ?
135 53 135 54 I ? Xe 210 82 237 93 4 2 Pb He ?
Np ? 233 91 Pa end Bellringer: 1. Write Fluorine-19 in nuclear notation. 2. Describe an alpha particle. 3. Complete the following nuclear equation: 135 4. STOTD135 53 I ? 54 Xe **you will need a periodic table and calculator for today! Nuclear Decay Radioisotopes decay at a certain rate:
A Half-life The time for half of a sample to decay Start with 100 g: after 1 half-life = 50 g after 2 half-lives = 25 g after 3 half-lives = 12.5 g after 4 half-lives = 6.25 g end Half-life Key words and numbers to look for in Half-life problems: Initial mass Final mass Half-life time Number of half-lives
Total amount of time How to solve 1. Pick out what you know about the problem 2. Underline key words and numbers 3. Figure out what the question is asking you Radioactive Decay 1. If you had 25 g of gold-198 how much is left after it has gone through 12 half-lives? 2. You have 10.0 g of francium-210. How many half-lives must pass for 2.5 g to be left? 3. If you start with 200 g of Pu-239 and there are 0.78 g left, how many half-lives have passed? 4. How much of a 100 g sample of gold is left after 8.10 days if its half-life is 2.70 days? end
Nuclear Decay Each isotope has a specific half-life Anywhere from a few seconds to billions of years Can never be changed Polonium-215 0.0018 seconds Sodium-24 15 hours Iodine-131 8.07 days Carbon-14 5730 years Uranium-235 704,000,000 years Uranium-238 4,470,000,000 years end
Bellringer: 1. Complete the following nuclear equations: 238 92 U 2. STOTD 234 90 4 2 Th He
Bellringer: 1. What is the atomic number for iron? 2. How many electrons does an electrically neutral atom of aluminum have? 3. How many protons does Argon-41 have? 4. STOTD Fission vs. Fusion Fission
Splitting a nucleus into smaller parts Lots of energy is produced from a very small mass 1 kg of U-235 = 17,000 kg of coal!!! Nuclear Power Stations and Atomic Bombs end Fission vs. Fusion Fusion
Nuclei combine to form a larger nucleus The sun/stars ~600 million tons of H is used every second Thermonuclear Bomb (H-Bomb) Scientists are attempting to make fusion power stations end Extremely difficult because you need high temperatures and high pressure
Fission vs. Fusion end When a series of nuclear fissions is triggered from the splitting of a single nucleus you get a chain reaction Bellringer: 1. Fill out the Venn Diagram below: 2. STOTD
Nuclear Waste Used nuclear fuel is held in swimming pools at the nuclear reactor 40 ft deep Water blocks radiation Kept for 10-20 years
Planned nuclear waste storage at Yucca Mountain Waste will be buried forever end Effects of Radiation Levels Dose (rem) 5-20 20-100 Effects Possible late effects and chromosomal damage Temporary reduction in white blood cells
Mild radiation sickness within a few hours 100-200 Vomiting, diarrhea, fatigue Reduction in resistance to infection 200-300 300-400 400-1000 end 1000-5000 Serious radiation sickness effects and hemorrhaging Lethal Dose to 10-35% of the population after 30 days Serious radiation sickness along with bone marrow and intestine destruction
Lethal Dose to 50-70% of the population after 30 days Acute illness, early death Lethal Dose to 60-95% of the population after 30 days Acute illness, death in days Bellringer: 1. Determine the number of protons, neutrons, and electrons in Silicon-28. 2. Draw a Bohr model for Oxygen-16. 3. STOTD Bellringer: 1. What do you know about the periodic table? 2. STOTD The Periodic Table By
1860 scientists had discovered 63 elements But there was no good way to organize them Scientists had to memorized everything This was changed by Mendeleev end The Periodic Table Mendeleevs Periodic Table: Elements with similar properties were placed in the
same column The mass of the elements increased along each row end The Periodic Table Mendeleev left several blank spaces in his periodic table For elements that had not been discovered yet He correctly predicted the properties of these elements based on the elements around them end
The Periodic Table The Modern Periodic Table: Based on Mendeleevs table Similar Properties are in the Same Column Columns are called Groups Numbered 1 to 18 (from left to right) Atomic Numbers increase going across the table
Rows are called Periods Numbered 1 to 7 (from top to bottom) end The Periodic Table This is the full Periodic Table As you can see it is REALLY long Way too long to fit on a page end The Periodic Table To make everything fit on 1 page, the Lanthanides and Actinides are moved to the bottom
end The Periodic Table Metals Left of the stair-step line Francium (Fr) is the most reactive Moving Good conductors of electricity and heat Mostly solids at room temperature High
away from Fr, metals become less reactive melting and boiling points Malleable and ductile end The Periodic Table Nonmetals Right of the stair-step line Fluorine (F) is the most reactive nonmetal Moving
away from F, nonmetals become less reactive Poor conductors of heat and electricity Mostly gases at room temperature Low Not melting and boiling points malleable and not ductile end The Periodic Table Metalloids
Touching the stair-step line Have properties between metals and nonmetals Depends on the temperature end The Periodic Table: Group Names end The Periodic Table Atomic Size Francium (Fr) is the largest atom
Helium (He) is the smallest atom The closer to Fr, the larger the atom Valence Electrons Electrons in the highest energy level Give Elements their Chemical Properties Group: 1 2 13 14 15 16 17 # of 1 2 3 4
5 6 7 Valence: end 18 8 Bellringer: Write down as many elements that you need to know for you element quiz as you can!! If you are ready to take the quiz verbally let me know! STOTD Bellringer: 1. Why are elements placed in columns?
2. What do we call a row on the Periodic table? 3. How many protons does the element in group 11, period 5 have? 4. STOTD Bellringer: 1. What are the family names for each group on the periodic table? 2. How many protons does the element in group 13, period 3 have? 3. Describe a beta particle. 4. STOTD
