Physical science test 1.18.17

Radioactive isotopes are used to determine the age of objects. The half-life of iodine-131 is approximately 8 days. If an object is found to have one-eighth of the radioactive iodine-131 remaining, how old is the object? A.) 1 day B.) 4 days C.) 24 days D.) 64 days

C.) 24 days

A geologist tested a sample of rock and discovered that it contained 2.5 x 10^-9g of radium-226. The geologist calculated that the rock sample originally contained 2.0 x 10^-8g of Ra-226.Given that the half-life of Ra-226 is 1,600 years, determine the age of the rock sample. A.) 1600 years B.) 3200 years C.) 4800 years D.) 6400 years

C.) 4800

Which type of radiation has the least penetrating power? A.) gamma B.) beta C.) alpha D.) X-ray

C.) alpha

Which of these changed can occur in a substance as energy of particles decreases? A.) The substance melts B.) The substance sublimes C.) The substance condenses D.) the substance evaporates

C.) condenses

What type of electromagnetic radiation is emitted by the decaying nucleus of a radioactive atom? A.) ultraviolet waves B.) infrared waves C.) gamma rays D.) X-rays

C.) gamma rays

An increased concentration of what ion characterizes a solution of a base in water? A.) hydrogen ion B.) hydronium ion C.) hydroxide ion D.) hydrochloride ion

C.) hydroxide ions

Isotopes of hydrogen react, forming the element helium as shown. This reaction is best classifies as which? A.) Nuclear decay B.) Nuclear fission C.) Nuclear fusion D.) Nuclear half-life

C.) nuclear fusion

The graph shows the results of the decay of the radioactive element, carbon-14(^14C) into the more stable element, nitrogen-14(^14N) Which could most likely be concluded from the information in the graph? A.) one half-life is about 28,650 years B.) carbon-14 (^14C) dating would be useful for one-million-year old fossils C.) the amount of carbon-14 will be undetectable in about 30,000 years D.) the carbon-14 in the sample will begin to increase in 29,000 years

C.) the amount of carbon-14 will be undetectable in about 30,000 years

Uranium-238 has a half-life of 4.46 billion years and is often analyzed through radiometric dating to find the ages of rocks. U-238 decays in a series that can be summarized by the equation shown below. 238 206 4 0 U -> Pb + x He + y e 92 82 2 -1 -1 How many alpha particles, x, and how many beta particles, y, are needed to balance the nuclear equation? A.) x=4; y=16 B.) x=5; y=32 C.) x=8; y=6 D.) x=16; y=22

C.) x= 8 ; y=6

Carbon 14 has a radioactive half-life of 5700 years. If an organism has 10 grams of carbon 14 in its body at the time of its death, how much carbon 14 will remain after 5700 years? A.) 10 g B.) 7.5 g C.) 5 g D.) 2.5 g

c.)5 g

A scientist determined that a rock sample contained 1.5 x 10^-10g of Uranium-235 and that the isotope had decayed for 2.0 half-lives. How much U-235 was present in the sample initially? A.) 3.8 x 10^-11 g B.)1.5 x 10^-10 g C.) 6.0 x 10^-10 g D.) 2.4 x 10^-5 g

c.)6.0 x 10^-10 g

Carbon-14 has a half-life of 5730 years. How much C-14 remains after 3 half-lives from an initial mass of 3.00 x 10^-8 g? A.) 3.75 x 10^-9 g B.) 1.50 x 10^-8 g C.) 6.00 x 10^-8 g D.) 2.40 x 10^-7 g

A.) 3.75 x 10^-9 g

The half-life of a radioactive isotope is the time required for one half-life of the initial mass to decay into a different element. The radioactive decay of iodine is shown on the graph. What is the half-life of radioactive iodine? A.) 8 days B.) 16 days C.) 32 days D.) 48 days

A.) 8 days

210 206 4 Po -> Pb + He 84 82 2 Which radioactive emission is a product of this decay? A.) alpha B.) beta C.) postiron D.) gamma

A.) Alpha

Atoms of which two elements will form an ionic bond? A.) Mg and Cl B.) N and O C.) Fe and Co D.) Rb and Al

A.) Mg Cl

Uranium emits a type of radiation that can be harmful to humans if inhaled or swallowed, but it will not penetrate human skin. which of the following describes the type of radiation emitted by uranium? A.) alpha radiation B.) beta radiation C.) neutron radiation D.) gamma radiation

A.) alpha radiation

When an atomic nucleus emits a beta particle, what happens to the atomic number of the atom? A.) increases by one B.) increases by two C.) decreases by one D.) decreases by two

A.) increases by one

Students tested the Ph of four different solutions using litmus paper and recorded the observations in the data table below. SOLUTION BLUE LITMUS PAPER RED LITMUS PAPER ________________ _____________________________ ____________________________ 1 BLUE RED 2 RED RED 3 RED BLUE 4 BLUE BLUE A.) solution 1 B.) solution 2 C.) solution 3 D.) solution 4

A.) solution 1

The process of spontaneous radioactive decay of atoms of unstable elements is best described by which statement? A.) a more massive particle absorbs energy and turns into a less massive particle B.) a more massive particle forms one or more less massive particles and emits energy C.) a less massive particle forms one or more massive particles and emits energy D.) a less massive particle absorbs energy and turns into a more massive particle

B a more massive particle forms one or more less massive particles and emits energy

The equation shows the radioactive decay of Iodine-131. 131 131 I -> Xe + particle 53 54 What is the identity of the particle being emitted? 0 A.) ℬ -1 1 B.) H 1 0 C.) ᵉ +1 4 D.) HE 2

0 A.) B -1

Plutonium-238 (Pu-238) decays according to the reaction shown. 238 4 Pu -> X + He 94 2 What is the identity of the radioisotope X? 238 A.) Cf 98 234 B.) U 92 242 C.) Cm 66 236 D.) Th 90

B.)

Which chemical equation is correctly balanced? A.) Mg(NO3)2 + K2CO3 -> MgCo3 +KNO3 B.) Mg(NO3)2 + K2CO3 -> MgCO3 + 2KNO3 C.) 2Mg(NO3)2 + K2CO3 -> 2MgCO3 +KNO3 D.) Mg(NO3)2 + 2K2CO3 -> MgCO3 + 2KNO3

B.)

Which equation represents a decomposition chemical reaction A.) 2S+3O2 ->2SO3 B.) 2NaCl -> 2Na + Cl2 C.) 2K + 2H2O -> 2KOH +H2 D.) Zn + 2HCl -> ZnCl2 +H2

B.)

An atom of the element fluorine can be represented by the bohr model shown below. if the atomic mass of this atom is 19, how many neutrons are in the nucleus A.) 9 B.) 10 C.) 19 D.) 28

B.) 10

Christopher drew a graph to show changes in the mass of Barium-122(Ba) during 10 minutes of radioactive decay Based upon the results, what is the half-life of barium-122 in minutes? A.) 1 B.) 2 C.) 5 D.) 10

B.) 2 half lives

A solution does not affect red litmus paper but it turns blue litmus paper red. what type of compound was added to water to form the solution? A.) salt B.) acid C.) base D.) alcohol

B.) Acid

What is the process that produces energy in the sun for billions of years? A.) fission B.) fusion C.) solar winds D.) solar radiation

B.) Fusion

Which occurs in fusion reaction between two atoms? A.) Energy is absorbed as a less stable element forms. B.) a new element is formed and energy is released. C.) energy is converted into mass and forms a heavier element. D.) the nuclei of the atoms are split apart and energy is released

B.) a new element is formed and energy is released

Smoke detectors use Americium-421, a radioactive isotope produced in nuclear reactors, to complete a sensing circuit. the radioactive decay product of Americium-241 is easily stopped by smoke particles, breaking the sensing circuit. What does Americium-241 emit when it decays? A.) gamma rays B.) alpha particles C.) beta particles D.) electrons

B.) alpha particles

Unsweetened chocolate has a very bitter taste. what does this taste indicate about some of the compounds in unsweetened chocolate? A.) are acidic B.) are basic C.) are neutral D.) are salts

B.) are basic

Why are beta particles able to penetrate objects better than alpha particles are? A.) because beta particles are larger than alpha particles B.)because beta particles are smaller than alpha particles C.) because beta particles are negatively charged, while alpha particles are neutral D.) because beta particles travel in a straight line, while alpha particles travel in waves

B.) because beta particles are smaller than alpha particles

Which of the following describes a difference between fission and fusion? A.) fusion required energy to form elements, and fission does not B.) fusion combines smaller nuclei, and fission does not. c.) fusion requires energy to start a reaction, and fission does not D.) fusion combines energy from reactions, and fission does not

B.) fusion combines smaller nuclei and fission does not

An alpha particle that is emitted as nuclear radiation has the same structure as A.) hydrogen nucleus B.) helium nucleus C.) neutron D.) electron

B.) helium nucleus

The reaction below releases enormous amounts of energy that could be used to provide power to homes and businesses What is this reaction called? A.) ionic bonding B.) nuclear fusion C.) radioactive decay D.) chemical decomposition

B.) nuclear fusion

Which of the following produces radioactivity? A.) the ionization of an atom B.) the fission of an atomic nucleus C.) an exothermic chemical reaction D.) a loss of energy by an electron

B.) the fission of an atomic nucleus

An isotope of radon gas, Rn-222, undergoes decay with a half-life of 3.8 days. How long does it take for the amount of Rn-222 to be decreased to one-sixteenth of the original amount? A.) 0.25 day B.) 7.6 days C.) 15.2 days D.) 60.8 days

C 15.2 days

Which compound results from covalent bonding? A.) NH4Cl B.) K2SO4 C.) NaCl D.) C6H12O6

D.) C6H12O6

What is nuclear fission? A.) a process in which the nucleus of an atom combines with the nucleus of another atom to form a heavier nucleus B.) a process in which the nucleus of an atom combines with the nucleus of another atom to form several lighter nuclei C.) a process in which the nucleus of an atom splits into individual protons and neutrons D.) a process in which the nucleus of an atom splits into two or more lighter nuclei

D.) a process in which the nucleus of an atom splits into two or more lighter nuclei

When an atomic nucleus emits an alpha particle, what happens to the atomic number of the atom? A.) increases by one B.) increases by two C.) decreases by one D.) decreases by two

D.) decreases by two

Which solution is most likely classified as a colloid? A.) soft drink B.) oxygen gas C.) water D.) fog

D.) fog

When two nuclei are combined into one nucleus, there is a slight change in mass and the release of a large amount of energy. what is this process called? A.) conversion B.) reaction C.) fission D.) fusion

D.) fusion

Half of a sample of cobalt-60 decays after 5.26 years to form atoms of another element. Half of sample iodine-131 decays after 8.1 days to form atoms of another element. which best explains this difference ? A.) iodine-131 has a smaller atomic number than cobalt-60 B.) iodine-131 has half the radioactive energy of cobalt-60 C.) iodine-131 has a smaller atomic mass than cobalt-60 D.) iodine has a shorter half-life than cobalt-60

D.) iodine has a shorter half life than cobalt

The lewis dot diagram for an unidentified element is shown below. which element could x be? A.) iron B.) chlorine C.) silicon D.) oxygen

D.) oxygen

what is one of the characteristics of an acidic compound? A.) pink color B.) slippery feel C.) unpleasant odor D.) sour taste

D.) sour taste