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What element has 65 protons?. What element has atomic number 65?. What element has 44 protons and 44 electrons?. What element has 21 protons?. What isotope has 34 protons and 26 neutrons?. Give the symbol for magnesium 24.
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Give the atomic number for an element that has a charge of -2 and contains 36 electrons
Give the mass number for an element that is neutral has 23 electrons and 24 neutrons
What product of radioactive decay can you safely hold in your hand?
Which is more dangerous inside a cell, an alpha or a beta particle? Why?
How did Rutherford discover that the nucleus is very small compared to the total volume of the atom?
What is the main difference between Thomson's and Rutherford's models of the atom?
Give the equation for the beta decay reaction for iodine-128
Give the equation for the beta decay reaction for nitrogen-16
What particle belongs in the following?Gold-197 --> _______________ + mercury-197
Give the particle that is missingIodine-127 --> ___________ + Helium-4
Fill in the blank__________________ --> Helium-4 + fluorine-19
Fill in the blank_______________ --> Holmium-165 + beta particle
Which of the following is ionizing radiation?microinfraredgammaradio
A radioactive isotope has a half-life of 5 hours. What percentage of radioactivity willremain after 25 years?
How old is a sample of iodine-128 if its half-life is 63 years and 12.5 % of the radioactivity remains.
1. Radioactivity kills cells. This is useful if the cells are unwanted bacteria or tumor cells. It is harmful if healthy good cells are affected.
6. Henry Becquerel left Uranium and photographic plates in the dark and found that the plates were developed by energy given off by the Uranium. He called this radioactivity.
8. Earnest Rutherford shot alpha particles at a thin piece of gold foil. Only 1 out of 2000 went through. This showed that most of the atom is empty space. The alpha particles that went through hit a positive nucleuswhich takes up a relatively small volume but contains most of the mass.
Dalton’s Thomson’s Rutherford’s
11, 12. Alpha versus beta radiation Alpha radiation is large but cannot penetrate the skin. Once inside the body and cells it can cause extensive damage because of its size and energy. It can get inside the body by inhalation as a gas or ingestion. Beta radiation is a fast moving electron which can penetrate the skin. It is blocked by metal. It can be damaging in cells but not as much as alpha.
Gamma radiation is electromagnetic radiation which can cause cell death and mutation. It is the most penetrating product from radioactive decay.
14. 0.63 moles16. 11460 years 17. The energy from the nucleus is released in nuclear reactions while the energy from the electrons is released in chemical reactions. Most of the energy in an atom is in the nucleus.
15. It is important to know how long a sample is going to be radioactive when in medical procedures and when storing waste. Exposure to people and other living organisms should be minimized.
Large doses of radioactivity can cause cell death or cell mutation by interacting with the cell’s DNA 21. Check answer on the periodic table.
Thomson’s model showed that the atom contained a subatomic particle, the electron. The atom according to Dalton was the smallest particle of matter and could not be broken up.
Rutherford showed that the atom contained a small positively charges nucleus and that most of the atom was empty space. Thomson had the positive charge spread throughout the atom.
19. a. Seaborgium-263, alpha particle, polonium-210, beta particle, lead-210 26, a. hydrogen-1 (proton),b. Helium-4, c. C. neutron, d. lithium-6
gold-198, 79 protons, 79 electrons, 119 neutrons Nitrogen-15-3, 7 protons, 1- electrons, 8 neutrons 28. The percentage of carbon-14 in a living organism remains constant until the organism dies. After that the nonradioactive carbon isotopes become a larger percentage. By measuring the percentage of carbon-14 (the radiaoctive isotope) the time since the organism died can be determined.