Ch. III and XI Flashcards Preview

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Flashcards in Ch. III and XI Deck (84):
1

Electrolysis

The use of electricity to cause a chemical reaction is called

2

During electrolysis of molten sodium chloride, chloride anions move to the

Anode, which is positively charged

3

Cathode rays are

Deflected by electric fields

4

J.J. Thompson measured the electron's

Mass-to-charge ratio

5

In his oil-drop experiment, Millikan determined the charge of an electron by

Noting that the drops had either a certain minimum charge or multiples or that charge

6

When Roentgen saw an X-ray image of his hand, the bones were darker than the glowing paper because the X-rays were

Absorbed more by bone than by flesh

7

Radioactivity arises from elements that

Are unstable and emit radiation

8

The mass of an alpha particle is about

Four times that of a hydrogen atom

9

Compared to the charge on an electron (designated 1^-), the charge on an alpha particle is

2^+

10

A beta particle is an

Electron

11

The mass of a gamma ray is

0u

12

The most persuasive evidence from Rutherford's gold-foil experiment was that

Most of the alpha particles went right through the foil, but a tiny fraction were deflected right back toward the source

13

Rutherford's gold-foil experiment showed that

The nucleus was tiny and positively charged

14

From his gold-foil experiment, Rutherford concluded that atoms mainly consist of

Empty space

15

The positively charged part of the atom is its

Nucleus

16

The three basic components of an atom are

Protons, neutrons, and electrons

17

The identity of an element is determined by its

Number of atoms

18

How many electrons are required to equal the mass of one proton?

About 1800

19

Which particles have approximately the same mass?

Protons and neutrons

20

A change in the number of protons in an atom produces an

Atom of a different element

21

The number of protons plus neutrons in an atom is its

Nucleon number

22

How many protons (p) and how many neutrons (n) are there in a 15/7N nucleus?

7 protons, 8 neutrons

23

A neutron atom has 19 electrons and 20 neutrons. Its atomic number is

19

24

An atom has 16 neutrons. It is

Not possible to identify the element from the number of neutrons

25

The symbol for the isotope potassium -40 is

40 K
19

26

When electrified in a gas-discharge use, different elements emit light that forms narrow lines that are

Characteristic of each particular element

27

When an electron in an atom goes from a higher energy level to a lower one, the electron

Releases energy

28

An atom in an excited state is one with an electron that has

Moved to a higher energy level

29

The maximum number of electrons in the first shell of an atom is

2

30

The maximum number of electrons in the third shell of an atom is

18

31

The main-shell electron configuration of aluminum is

2, 8, 3

32

The main-shell electron configuration of sulfur is

2, 8, 6

33

The shape of a 1s orbital is

Spherical

34

The maximum number of electrons in an atomic orbital

Is always 2

35

Which of the following subshells has the highest energy?

3p

36

What is the lowest-numbered main shell to have "d" orbitals?

3

37

Which of the following atoms has a half-filled subshell in the ground state?

Nitrogen

38

Which subshell has a total of three orbitals?

P

39

In what main shell is a 3d subshell located?

3

40

The electron capacity of the 4p subshell is

6

41

Which pair of elements has the most similar chemical properties?

Cl and Br

42

Elements within a period of the periodic table have the same number of

Occupied main shells

43

The valence-shell electron configuration of the halogens is

ns^2 np^5

44

The alkali members are of group

1A

45

What is the total number of valence electrons in an atom of bromine?

7

46

Which of the following sets of elements exhibits the most similar chemical properties?

Li, Na, and K

47

In the ground state, atoms of a fourth period element must have

Electrons in the fourth shell

48

What percentage of background radiation comes from natural sources?

82%

49

The largest source of natural background radiation is

Radon

50

At present levels of exposure, which of the following forms of radiation is most likely to give you cancer?

Medical X-rays

51

What are the mass and the charge, respectively, of positron particles?

0, +1

52

What particle is needed to complete the following nuclear equation?

9/4 Be + ___ ----> 12/6 C + 1/0 n

Alpha particle

53

Emission of which of the following will result in an increase of 1 in atomic number?

Beta particle

54

Emission of which of the following will result in no change in atomic number or nucleon number?

Gamma ray

55

For which type of radioactive decay is an electron found on the left side of the equation?

Electron capture

56

Which of the following is the largest particle?

Alpha particle

57

A patient is given a 48-mg dose of technetium-99 m (half-life 6.0 h) to treat a brain cancer. How much of it will remain in his body after 36 h?

0.75 mg

58

What is the half-life of arsenic-74 if a 50.0 g sample decays to 6.25 g in 53.7 d?

17.9 days

59

Of a 64.0-g sample of strontium-90 (half-life 28.5 y) produced by a nuclear explosion, what mass in grams would remain unchanged after 285 y?

0.0625 g

60

Lead-210 (half-life 22.26 y) can be used to date skeletal remains. About how old is a bone that has an activity of 2.0 Bq if new bone has an activity of 16 Bq?

67 y

61

About how old is a piece of wood from an aboriginal burial site that has a carbon-14 (half-life 5370 y) activity of 3.9 counts/min per gram of carbon? Assume that the carbon-14 activity of the wood was 15.6 counts/min per gram of carbon at the time of the burial.

11,460 g

62

What isotope of formed in the following artificial transmutation?

14/7 N + 1/0 n ---> 1/1 H+ ___

14 C or Carbon-14
6

63

What isotope is formed in the following artificial transmutation?

9/4 Be + 1/1 H ---> 4/2 He + ___

6 Li or Lithium-6
3

64

What isotope is formed in the following artificial transmutation?

27/13 Al + 4/2 He ---> 1/0 n + ___

30 P or Phosphorus-30
15

65

Iodine-131 is sometimes used for detecting leaks in underground pipes because

It has a short half-life

66

What is used to irradiate foodstuffs to extend shelf life?

Gamma rays

67

Which of the following isotopes is used in radiation therapy?

Cobalt-60

68

Which of the following isotopes is used in determining bone density?

Gadolinium-153

69

Which of the following isotopes is used for detecting heart problems during a treadmill stress test?

Thallium-201

70

Which of the following isotopes is used in thyroid diagnosis and therapy?

Iodine-131

71

What form of radiation is detected in PET scans?

Positron

72

Which of the following pairs represent the least and most penetrating types of radiation?

Alpha/Gamma

73

Which form of radiation requires a thin sheet of aluminum to be stopped?

Beta particles

74

A Geiger counter registered 50 Bq or activity from an unknown type of radiation. A piece of paper inserted between the source and the counter caused the reading to drop to about 2 Bq. The radiation was mostly

Alpha particles

75

Helium has a particularly high binding energy per nucleon, which means that it

Is more stable than H and Li

76

The most stable nuclei are those of

Iron

77

Nuclei with nucleon numbers greater than that of iron are

Less stable than that of iron

78

The isotope used in uranium fission reactions is

Uranium-235

79

What fraction of natural uranium is the fissionable isotope?

80

The uranium isotope from which fissile plutonium-239 is made is

Uranium-238

81

Strontium-90 substitutes for calcium in bones because Sr and Ca

Are in the same group of the periodic table

82

Many people in the Chernobyl and Tukushima areas were given large doses of potassium iodide to limit the uptake of iodine-131 and its concentration in the

Thyroid

83

Which of the following is not one of the isotopes produced by fission that presents the greatest hazard to people?

Iron-59

84

Which of the following radioisotopes in fallout is dangerous mainly because it becomes concentrated in the thyroid gland?

Iodine-131