PHSC 1: Ch.12

98) If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number of the element?

A) 31

79) If a neutral element has the following chemical notation, how many electrons does it have? carbon-13

A) 6

65) If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19

A) 9

71) If a neutral element has the following chemical symbol, how many electrons does it have?235 U 92

A) 92

70) Which element has the atomic number 9?

A) F

34) Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom s size?

A) Protons contribute more to an atom's mass while electrons contribute more to its size.

26) Which of the following elements is in the fourth period?

A) chromium (Cr)

57) Which of these properties describes a metal?

A) conducts heat very well

2) An element is best described as a material

A) consisting of only one type of atom.

77) Which of the following statements describes an isotope?

A) element with the same number of protons but a different number of neutrons.

3) An electron de-excites from the fourth quantum level to the third and then directly to the first. Two frequencies of light are emitted. How do their combined energies compare to the energy of the single frequency that would be emitted by de-excitation from the fourth level directly to the first level? Answer: The combined energies of the two frequencies emitted by the one electrons is

A) equal to the energy of the single frequency.

17) Helium(He) is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table because

A) helium is most similar to other group 18 elements.

50) Which of the following elements is an alkali metal?

A) lithium (Li)

21) Would you use a physical model or a conceptual model to describe the following: the brain; the mind; the solar system; the beginning of the universe?

A) physical; conceptual; physical; conceptual

91) If a neutral element has 8 neutrons and 7 electrons, which expression correctly identifies the element?

B) 15 N 7

63) The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?

B) 26

20) Which of the following could not be represented by a conceptual model?

B) the floor plan of a house

38) Which of the following is most easily understood to be quantized?

B) the number of eggs in an egg carton

27) Which of the following is not a nonmetal?

B) titanium (atomic no. = 22)

84) If a neutral element has the following chemical symbol, how many electrons does it have?18 O 6

C) 6

44) Boron has primarily two isotopes, one with an atomic mass of 11 amu and another with an atomic mass of 10 amu. If the abundance of the boron atom with a mass of 11 amu is 18.9 percent and the abundance of the other isotope is 81.1 percent, what would be the average mass of the boron atom?

D) 10.19 amu

82) The isotope lithium-7 has a mass of 7.0160 atomic mass units, and the isotope lithium-6 has a mass of 6.0151 atomic mass units. Given the information that 92.58 percent of all lithium atoms found in nature are lithium-7 and 7.42 percent are lithium-6, calculate the atomic mass of lithium, Li (atomic number 3).

D) 6.942 amu

6) The following statement describes which subatomic particle best?It is electrically charged.

D) A and B(an electron,a proton)

73) How might the spectrum of an atom appear if its electrons were not restricted to particular energy levels?

D) A broad spectrum of all colors would be observed.

14) What is the approximate mass of a carbon atom in atomic mass units (amu)? How about a carbon dioxide molecule?

D) A carbon atom has a mass of about 12 amu. Carbon dioxide would then have a mass of 44 amu.

23) How is the term photon related to the term quantum?

D) A quantum of light is actually one photon.

78) The element bromine, Br (atomic number 35), has two major isotopes of similar abundance, both around 50 percent. The atomic mass of bromine is reported in the periodic table as 79.904 atomic mass units. Choose the most likely set of mass numbers for these two bromine isotopes.

D) Br-79, Br-81

95) Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom?

D) D(empty)

7) If all the molecules of a body remained part of that body, would the body have any odor?

D) No, because there would be no molecules traveling to our nose.

49) What does the following element description actually mean?238 U 92

D) a uranium atom with 92 protons and 146 neutrons

66) Which of the following is a metalloid?

D) antimony (atomic no. = 51)

1) Elements that are in the same ________ have a tendency to have very similar chemical properties due to periodic trends.

D) group

56) Which of the following is not the name of a chemical family?

D) heavy metals

96) If an element has 10 protons and 11 neutrons and 10 electrons, which expression correctly identifies the element?

D) neon-21

8) Which of the following describes a nonmetal?

D) poor conductor of electricity

35) The mass number of an element is

D) the sum of the protons and the neutrons.

11) An element found in another galaxy exists as two isotopes. If 80.0 percent of the atoms have an atomic mass of 80.00 atomic mass units and the other 20.0 percent have an atomic mass of 82.00 atomic mass units, what is the atomic mass of the element?

E) 80.4 atomic mass units

22) The following statement describes which subatomic particle best?It has a relatively large mass.

E) B and C(a proton, a nutron)

15) The following statement describes which subatomic particle best?It is a nucleon.

E) B and C(a proton,a neutron)

31) The atomic symbol represents

E) Only two of the above.( the history of the element,the name of the element,the number of electrons in an atom of an element.)

64) Which of the following physical properties would you expect for krypton (Kr)?

E) a gas at room temperature

83) Which color of light comes from the higher energy transition, red or blue?

A) Blue is a higher frequency and therefore corresponds to a higher energy level transition.

36) Where did the atoms that make up a newborn baby originate?

A) In the explosions of ancient stars.

4) If you remove two protons and two neutrons from a gold atom (Au), what new element is formed?

A) Ir

39) Which element has the atomic number 12?

A) Mg

93) What is the relationship between the light emitted by an atom and the energies of the electrons in the atom?

A) The greater the frequency of a photon of light, the greater the energy packed into that photon.

54) An element has two different isotopes: one that weighs 65 amu and another that weighs 67 amu. If the average atomic mass of all the isotopes is 66.5 amu, what can be said about the relative abundance of the isotopes?

A) The isotope with the mass of 67 is more abundant than the isotope with the mass of 65.

28) What do the electron configurations for all the group 18 noble gases have in common?

A) Their outermost occupied shells are filled to capacity

81) Considering how small atoms are, what are the chances that at least one of the atoms exhaled in your first breath will be in your last breath?

A) Very probable because atoms are incredibly small.

92) If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?

A) atomic mass, 99 amu; Technetium

76) If two protons and two neutrons are removed from the nucleus of an oxygen atom, a nucleus of which element remains?

A) carbon-12

89) The shell model is an example of a

A) conceptual model.

58) Would you use a physical model or a conceptual model to describe the following: a gold coin, dollar bill, car engine, air pollution, virus, spread of sexually transmitted disease?

A) physical model: gold coin, car engine, virus; conceptual model: air pollution, spread of sexually transmitted disease; dollar bill, which could represent wealth, may well be described by either model.

52) Which of the following elements will most likely be shiny and malleable?

B) rhodium (Rh)

51) Germanium, Ge (number 32), computer chips operate faster than silicon, Si (number 14), computer chips. So how might a gallium, Ga (number 31), chip compare with a germanium chip?

C) A gallium chip would be even faster because the gallium is more metallic.

97) An atom absorbs or emits only particular frequencies of light. White light bends into a glass prism and separates into a rainbow of colors. In which of these two scenarios does the electromagnetic radiation behave as a wave? As a particle?

C) Absorption of light shows particle behavior while bending of light shows wave behavior.

60) Which of the following elements are in the same period as magnesium (Mg)?

C) Cl

85) What is the valence shell?

C) It is the outermost shell of electrons in an atom.

33) Why isn't dirt listed in the periodic table?

C) The periodic table lists only elements made of one kind of material. Dirt is a mixture of elements and compounds.

100) Which of the following might best explain the reason why electrons are restricted to certain energy levels in an atom?

C) They behave like restricted waves and are self-reinforcing.

88) In what sense can you truthfully say that you are a part of every person around you?

C) We are continually exchanging our atoms.

19) How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?

C) When an electron wave is confined, it is reinforced only at particular frequencies.

30) What does the following element description actually mean?18 O 6

C) an oxygen atom with 6 protons and 12 neutrons

67) If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element?

C) argon-38

29) You could swallow a capsule of germanium, Ge (atomic number 32), without significant ill effects. If a proton were added to each germanium nucleus, however, you would not want to swallow the capsule because the germanium would

C) become arsenic.

62) If an atom were the size of a baseball, its nucleus would be about the size of a(n)

C) flea.

55) Which of the following elements is a transition metal?

C) silver (Ag)

53) Which chemical family is composed almost entirely of man-made elements?

C) the actinides

40) What subatomic particle by itself is least affected by electromagnetic radiation?

C) the neutron

72) Oxygen, O, (number 8), sulfur, S, (number 16), and selenium, Se, (number 34) have such similar chemical properties because

C) their outermost shells contain the same number of electrons.

61) When a rainbow of colors of light are combined into a single ray it forms

C) white.

68) How do we account for the great variety of substances in the world?

D) There are many possible combinations of atoms.

5) Which are older, the atoms in the body of an elderly person or those in the body of a baby?

D) They are of the same age, which is appreciably older than the solar system.

47) Does a shell have to contain electrons in order to exist?

D) Two of the above are reasonable answers. (A shell is just a conceptual model; hence; it doesn t really exist with or without the electron,A shell is just a region of space which may or may not contain electrons,A shell is a form of energy that requires electrons in order to exist.)

94) Why can't we see atoms?

D) We see with light energy and the wavelength is larger than the object and so it is not reflected.

41) What does the following element description actually mean? hydrogen-2

E) a hydrogen with one neutron and one proton

45) Which of the following images could describe an element at the atomic level?

E) all of the images

99) Which of the following statements is true about Bohr s planetary model of the atom?

E) none of the above(no to The electrons smoothly move from one orbit to the next,It is a physical mode,The energy difference between the orbits is continuous,The electrons actually orbit around the nucleus.)

10) Which of the following best explains what is happening when an atom emits light?

B) An electron is dropping from a higher to a lower energy level with the difference in energy between the two being emitted as light.

86) Which element would have chemical properties the most similar to chlorine (Cl)?

B) Br

80) Which of the following elements are in the same group as silicon (Si)?

B) C

24) What was Niels Bohr's explanation for the observation of atomic spectra?

B) Electrons could only move in discrete energy steps within an atom.

13) What is the main tenet of Plank's quantum hypothesis?

B) Energy comes in discrete packets of a certain minimum size.

90) How is it possible to deduce the identity of an element from its electron configuration?

B) If the atom is electrically neutral, the number of electrons corresponds to the atom s atomic number.

12) Which of the following statements does not describe a proton?

B) It orbits around the nucleus of an atom.

25) Should the periodic table be memorized? Why or why not?

B) No. The periodic table is a reference to be used, not memorized.

43) How can a hydrogen atom, which has only one electron, have so many spectral lines?

B) One electron can be boosted to many different energy levels.

74) If you remove two protons and two electrons from a sulfur atom (S), what new element is formed?

B) Si

37) Why are the atomic masses listed in the periodic table not whole numbers?

B) The atomic masses are average atomic masses.

9) Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation.

B) The neutron lacks an electrical charge.

59) What property of an electron makes it possible to use electron microscopes?

B) They have shorter wavelengths than visible light.

69) Consider the various frequencies of the three photons emitted from the following three individual electron transitions in the figure below: n=3 to n=2; n=2 to n=1; n=3 to n=1. These transitions would produce three spectral lines in a spectroscope. If the energy spacing between the levels were equal, would this affect the number of spectral lines?

B) Yes, two otherwise separate lines would converge into a single more intense line.

87) Which of the following best describes a conceptual model of an atom?

B) a model that illustrates the tendency of an atom to undergo chemical bonding

75) Which of the following elements is a gas at room temperature?

B) argon (Ar)

16) Which of the following elements is a halogen?

B) chlorine (Cl)

48) Which of these does not describe a metal at room temperature?

B) gas

46) Strontium, Sr (number 38), is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues (calcium, Ca, number 20). This fact relates to the organization of the periodic table in that strontium and calcium are both

B) in group 2 of the periodic table.

42) How many electrons are there in the third shell of sodium, Na (atomic number 11)?

B) one

32) Which atom is largest?

D) Rb

18) Some older cars vibrate loudly when driving at particular speeds. For example, at 65 mph the car may be most quiet, but at 60 mph the car rattles uncomfortably. How is this analogous to the quantized energy levels of an electron in an atom?

D) The vibrating car is analogous to one of the energy levels of the electron, which is the point at which the electron experiences resonance.