Chapter 2 section 2.1-2.4

how does the mass of a proton compare to the mass of a neutron?

they are relatively similar at 1 amu

Overall atoms have no charge because the number of protons is equal to the number of electrons (t/f)

true

atoms and subatomic particles prequalified as matter (t/f)

true

determine the number of protons, electrons, and neutrons present in a chlorine atom that has a mass number of 35, write element in symbolic notation

17 protons, 17 electrons; neutrons= mass number - protons= 18 neutrons; ^35v17Cl

how much has human exposure increased since the 1980s and why?

40%, due to increased use of radiation in medical procedures

how much radiation is the average person exposed to annually from all sources

620 mrem or 6.2mSv

when is an isotope considered radioactive according to its atomic number

83 and higher

How can an alpha particle be written, and what is unique about it?

^4v2He; it contains 2 protons and 2 neutrons; it's a helium atom without electrons, it carries a 2+ charge form its 2 protons

symbolic notation

a method used to represent an atom's atomic symbol, mass number, and atomic number; ^12v6C --> 12= mass number, C= atomic symbol, 6= atomic number

how many simultaneous chest X-rays would a person have to endure to have an exposure of 20,000 mrem, causing a temporary decrease in WBCs? based on this example, is one chest X-ray harmful?

a typical chest X-ray provides a 10 mrem dose. in order to simultaneously get exposure to 20,000 mrem, you'd have to simultaneously get X-rayed 2000 times. no, one chest X-ray is not harmful

determine the number of protons, neutrons, and electrons: a) an iodine atom that has a mass number of 131 b) a potassium atom that has a mass number of 39 c) a helium atoms that has a mass number of 4 d) a carbon that has a mass number of 14

a) 53 protons, 78 neutrons, 53 electrons b) 19 protons, 39-19= 20 neutrons, 19 electrons c) 2 protons, 4-2= 2 neutrons, 2 electrons d) 6 protons, 14-6= 8 neutrons, 6 electrons

determine the number of protons, electrons, and neutrons: a) ^15v7N b) ^14v7N c) ^16v7N

a) 7 protons, 8 neutrons, 7 electrons b) 7 protons, 7 neutrons, 7 electrons c) 7 protons, 9 neutrons, 7 electrons

what is the mass number for the following: a) an oxygen atom that contains 8 neutrons b) a fluorine atom that contains 10 neutrons

a) 8 protons + 8 neutrons= 16 b) 9 protons = 10 neurons= 19

there are three naturally occurring isotopes of magnesium: magnesium-24, mg-25, mg-26. a) how many neutrons are present in each isotope b) write complete symbolic notation for each isotope c) based on the average atomic mass in the periodic table, which isotope of mg is the most abundant

a) Mg-24: 12 protons, 24-12= 12 neutrons, 12 electrons; Mg-25: 12 protons, 25-12= 13 neutrons, 12 electrons; Mg-26: 12 protons, 14 neutrons, 12 electrons b) ^24v12Mg; ^25v12Mg; ^26v12Mg c) Mg-24

how can you determine the following: a) the number of protons in an atom b) the number of neutrons in an atom c) the number of electrons in an atom

a) atomic number, b) mass number - atomic number, c) same as the number of protons

provide the name and the atomic symbol of the element: a) 7 b) 16 c) 50 d) 30 e) 27 f) 79 g) 19 h) 82 i) 33 j) 11

a) nitrogen-N b) sulfur-S c) tin-Sb d) zinc-Zn e) cobalt-Co f) gold-Au g) potassium-K h) lead-Pb i) arsenic-As j) sodium-Na

what can be determined from the following: a) mass number, b) atomic number c) mass number - the atomic number

a) the number of neutrons??? b) the number of protons c) the number of neutrons

if the symbol for an alpha particle is ^4v2He, explain how an alpha particle differs from a helium atom

an alpha particle is a helium nucleus. there are no electrons in an alpha particle

in some atoms with an unstable nucleus, one of the neutrons may eject a high-energy electron called what? how can it be written

beta particle; carries a charge of 1- ; ^2v-1e (e- is the symbol for the electron)

what is the charge on a beta particle, alpha particle, and positron?

beta: 1-, alpha: 2+, positron: 1+

how are x-rays generated

by high-energy electron processes; they are not quite as high energy as gamma rays though

how many electrons must carbon and lithium contain to be considered neutral?

carbon: 6, lithium: 3

copper has two naturally occurring isotopes: copper-63 and copper-65. Based on the atomic mass from the periodic table, which of these is more abundant?

copper-63

space occupied by an electron

electron cloud

negatively charged particles

electrons

positron decay events used in the medical imaging technique called PET

emissions (positron emission tomography)

how often are we exposed to ionizing radiation in the form of cosmic rays from outer space, radon gas, and other naturally radioactive elements in the earth

every day

all atomic nuclei are radioactive (t/f)

false, most naturally occurring isotopes have a stable nucleus (therefore not radioactive)

no element with an atomic number lower than 83 is radioactive (t/f)

false, there are some

we are not exposed to human-made sources of radiation during medical and dental treatments, during air travel, and from consumer products (tvs and smoke detectors) (t/f)

false, we are exposed (one transcontinental flight exposes a person to an additional 2-3 mrem, one X-ray exposes a person 0.1 mrem or 1uSv)

radiation is a form of energy that we only get from human-made sources (t/f)

false: it is from both natural and human-made sources

the annual dose for all radiation sources is very harmful to humans (t/f)

false; generally the annual dose is not harmful

most of an atom consists of full space (t/f)

false; most of an atom consists of empty space

all ionizing radiation has the same amount of energy (t/f)

false; radiation of higher energy can penetrate farther into a tissue, affecting cells located deeper in the body

protons and neutrons have very different mass' (t/f)

false; they both have roughly the same mass (1 amu)

high-energy radiation emitted during radioactive decay, have no mass, and are rays instead of particles

gamma rays

which form of ionizing radiation is the most similar to X-ray radiation? How is it different?

gamma rays; x-rays only travel several meters, only penetrate through to tissue, not bone, and can be shielded by a lead apron or concrete barrier; gamma rays travel several hundred meter, fully penetrate body, and can be shielded by thick lead concrete or a water layer

if high doses of radiation can be harmful, what is the rationale behind radiation therapy for people with cancer

in small doses, radiation can kill rapidly dividing cells such as WBCs, and cancer cells

atoms of the same element with different mass numbers

isotopes

how does the mass of an electron compare to the mass of a proton?

it is significantly smaller at 1/2000 amu vs 1 amu; it does not significantly contribute to the mass of an atom

what is the number of protons plus the number of neutrons?

mass number; mass number= protons + neutrons

What is the more common unit used to measure biological damage

millirem (mrem)

neutrons can be used to cause radioactive decay if they are aimed at a radioisotope and added to the nucleus, what is this known as

neutron capture therapy, causing boron-10 to become boron-11 which then undergoes radioactive decay; a neutron has no charge and is represented as ^1v0n

uncharged particles

neutrons

which form of ionizing radiation has the greatest penetrating power?

neutrons

Where are the subatomic particles located in the atom?

protons and neutrons are located in the nucleus, the electrons are found in constant motion around the nucleus in the electron cloud

elements that spontaneously emit radiation from their nucleus

radioactive

isotopes that are not stable can become stable by spontaneously emitting radiation from their nuclei. what is this called

radioactive decay

why is radiation dangerous to living organisms?

radioactive emissions contain a lot of energy, when emitted they will interact with any atoms they come into contact with (whether or not its living)

what are elements (like uranium) that emit radiation through radioactive decay

radioactive isotopes or radioisotopes

2.2

section

2.3

section

2.4

section

what is the SI unit used to measure the effect of biological damage

sievert (Sv)

what indicates the number of protons present in an atom of each element

the atomic number

the mass of the isotope carbon-12 is exactly 12amu. the atomic mass for carbon is 12.01 amu. Explain this difference

the isotope carbon-12 contains exactly 6 protons and 6 neutrons. the atomic mass as seen on the periodic table is an average mass, taking into consideration the abundance of all the carbon isotopes. because about 1% of the carbon isotopes are carbon-13, the atomic mass is slightly higher Tham 12 amu

how are atomic mass and mass number similar? how are they different?

the isotopes have the same number of protons (therefore the same atomic number), but different numbers of neutrons (different mass numbers)

isotopes have the same number of protons (therefore the same atomic number), but different numbers of neutrons (different mass numbers) (t/f)

true

several radioisotopes can be mined from earth and prepared in scientific laboratories (t/f)

true

some radioisotopes with an unstable nucleus will change a proton to a neutron and emit a positron (t/f)

true

the number of electrons is equal to the number of protons (t/f)

true, because atoms are neutral

an isotope can be non-radioactive and radioactive if the neutron is increased (t/f)

true; Ga-69 is nonradioactive, Ga-67 is radioactive

1 sv = 100,000 rem or 100 mrem (t/f)

true; Sv units take into account the activity (or amount) and type of radiation absorbed per kilogram of body tissue

ionizing radiation

when alpha and beta particles, neutrons, positrons, gamma rays, and X-rays interact with another atom they have the effect of ejecting one of that atom's electrons. this causes the atom to be more reactive and less stable

when are gamma rays released

when an unstable nucleus rearranges to a more stable state; neither the charge nor the mass of the radioisotope will change

not emitted from a radioactive nucleus, but are commonly used in a clinical setting and share many properties with gamma rays

x-rays

subatomic particles

protons, neutrons, electrons

some of the naturally occurring isotopes of tin are tin-118, tin-119, tin-120, and tin-124 a) how many neutrons are present in each isotope b) write complete symbolic notation for each isotope

a) tin-118: 50 protons, 68 neutrons, 50 electrons; tin-119: 50 protons, 69 neutrons, 50 electrons; tin-120: 50 protons, 70 neutrons, 50 electrons; tin-124: 50 protons, 74 neutrons, 50 electrons b) ^118v50Sn; ^119v50Sn; ^120v50Sn; ^124v50Sn

based on its penetrating power into tissue, which form of ionizing radiation is the least dangerous

alpha radiation

what units are used for describing the mass of a proton or neutron?

amu (atomic mass unit)

determine the number of protons, neutrons, and electrons: a) ^18v8O b) ^40v20Ca c) ^108v47Ag d) ^207v82Pb e) ^2v1H f) ^27v13Al g) ^23v11Na h)^79v35Br

neutrons= mass umber - protons a) 8 protons, 10 neutrons, 8 electrons b) 20 protons, 20 neutrons, 20 electrons c) 47 protons, 61 neutrons, 47 electrons d) 82 protons, 125 neutrons, 82 electrons e) 1 proton, 1 neutron, 1 electron f) 13 protons, 14 neutrons, 13 electrons g) 11 protons, 12 neutrons, 11 electrons h) 35 protons, 44 neutrons, 35 electrons

a routine dental exam often includes four bite-wing X-rays, exposing a patient to a total of 5 mrem of radiation. would this cause radiation sickness in the patient? if so, what would be the effects

no; you would have to receive 4000 sets of X-rays before observing a clinical effect (starts to occur at 20,000 mrem). this is more than a dental technician would likely take in a day

energy given off spontaneously from the nucleus of an atom

nuclear radiation

Center of an atom

nucleus

atomic mass unit (amu)

one twelfth the mass of a carbon atom containing six protons and 6 neutrons (12 amu)

what are the first three forms of nuclear radiation that were discovered?

positively charged alpha particle, negatively charged beta particle, and neutral gamma; two other forms are positron (+ charged) and neutron (neutrally charged)

what radiation has the same mass as a beta particle but is positively charged

positron; ^0v1e

the neutron that emits the beta particles becomes a ______ as a result

proton

name the subatomic particles that make up all atoms, and the charge and relative mass associated with each

proton: positively charged, 1 amu; electron: negatively charged, 1/2000 amu (does not contribute significantly to mass); and neutron: no charge, 1 amu

positively charged particles

protons

write the symbolic notation for atoms with: a) 5 protons and 6 neutrons b) 35 protons and 46 neutrons c) 14 protons and 14 neutrons d) 54 protons and 70 neutrons e) 3 protons and 4 neutrons f) 7 protons and 10 neutrons g) 15 protons and 16 neutrons h) 46 protons and 60 neutrons

protons + neutrons = mass number a) ^11v5B b) ^81v35Br c) ^28v14 Si d) ^124v54Xe e) ^7v3B f) ^17v7N g) ^31v15Ga h) ^106v46Pd