Atom Test Period 8

Aristotle proposed that the universe consists of four elements: __________

• Hydrogen, oxygen, nitrogen, and carbon (HONC)

• Hydrogen, oxygen, calcium, and a fourth element he simply called "metal"

• Unobtainium, element X, vibrainium, and adamantium

• Air, wind, earth, and fire

• Air, fire, earth, and water

Magnesium has three of it's own isotopes.   78.7% is Magnesium-24.  10.13% is Magnesium-25.  11.17% is Magnesium-26.Calculate the average atomic mass of Magnesium, to one decimal place. Do not include units. For example, if you believe the answer is 24.1439 amu, simply enter 24.1

Imagine that Element A occurs naturally in the environment.Scientists have found 612 atoms of A-15, 829 atoms of A-16, and 244 atoms of A-17.Calculate the average atomic mass of the element A to two decimal places.Do not include units. For example if you believe the answer is 438.321466 amu, simply enter 438.32

19.9% of all Boron atoms are Boron-10. 80.1% of all boron atoms are Boron-11.Calculate the average atomic mass of Boron, to one decimal place. Please choose the closest answer.

• 10.8 amu

• 10.7 amu

• 21.0 amu

• 10.6 amu

• 10.5 amu

When the negative pole of a magnet is placed near a beam of electrons, the beam is deflected away from the magnet. This suggests that

• Electrons have no charge

• Electrons have a positive charge

• Electrons have a negative charge

• Electrons can have either a positive or negative charge depending on their magnetic field.

• Electrons have no mass

• Electons travel in curved paths and are therefore waves of energy, not matter.

Over the last several years, genuine images of molecules have appeared in the scientific literature

• True

• False

Antoine Lavoisier demonstrated in the eighteenth century that the products of all chemical reactions have the same total mass as the reactants- this is now known as the law of conservation of mass. The key device he used to determine this was a(n) _______________

• Optical microscope

• Calorimeter

• Double pan balance

• Flame ionization spectrometer

• Primitive type of photography known as a daguerrotype

Why is beryllium likely to bond to oxygen?

• Because beryllium is likely to lose two electrons, and oxygen is likely to gain two electrons

• Because beryllium is likely to gain one electron and oxygen is likely to lose one electron

• Because beryllium is likelty to gain two electrons, and oxygen is likely to lose two electrons

• Because beryllium has four valence electrons and oxygen has 8 valence electrons

• Because beryllium oxide has no valence electrons

A gold atom has sixteen valence electrons

• True

• False

How many protons, neutrons, and electrons are in the following ion? 

• Ten protons, eleven neutrons, twelve electrons

• Eleven protons, twelve neutrons, thirteen electrons

• 12 protons, 11 neutrons, eleven electtons

• 11 protons, 12 neutrons, ten electrons

• 11 protons, 10 neutrons, 12 electrons

Which atom is predicted to be radioactive?

• Na-23

• Au-196

• H-3

• Li-7

Which of the following atoms or ions has six valence electrons

• Carbon

• The oxygen dianion, O^2-

• Oxygen

• The carbon dication, C²⁺

An atom is found to have ten protons and fourteen neutrons in the nucleus, and outside of the nucleus this atom contains ten electrons, with two electrons in the first shell and eight electrons in the second shell. Which statement best describes this atom?

• This atom is chemically stable, not radioactive, and is unlikely to form an anion or a cation

• This atom is chemically unstable, radioactive, and is likely to form an anion

• This atom is chemically unstable, not radioactive, and is likely to form a cation

• This atom is chemically unstable, not radioactive, and is likely to form an anion

• This atom is chemically stable, and is radioactvie

• This atom does not exist since none of the electrons are in the nucleus.

Which element has fourteen electrons in the third shell?

• Scandium, atomic number 21

• Iron, atomic number 26

• Lutetium, atomic number 71

• Silicon, atomic number 14

This is a true or false question.The two atoms described below are both isotopes of fluorine (F). atom A: Nine protons, ten neutrons, nine electronsatom B: Nine protons, nine neutrons, nine electrons

• True

• False

An atom of Pb-208 would have ? electrons.

• 208

• 82

• 126

Silver has 2 isotopes.The first isotope has a mass of 106.905 amu (52%).The second isotope occurs in 48% abundance (48%).The atomic mass of silver is 107.868 amu.Which is closest to the mass of the second isotope? Please choose the closest answer.

• 108.911 amu

• 108.684 amu

• 109.213 amu

• 108.524 amu

The ion below has never been observed...Why?   2 protons, 2 neutrons, 3 electrons 

• Helium is a noble gas with a full set of valence electrons and therefore will not form an ion.

• Helium is far more likely to lose an electron and form a cation, rather than gain an electron and form an anion as shown

• This ion is radioactive and would decompose so rapidly it cannot be observed

• This is not an ion, it is an atom

A zinc atom has eighteen electrons its third shell

• True

• False

An atom is fundamentally different from an ion. This is because an ion...

• Never has an equal number of protons and electrons, and an atom always has an equal number of protons and electrons.

• Always has the same number of protons and neutrons; for atoms the number of protons may be different than the number of neutrons.

• Always has more electrons than protons; atoms always have the same number of protons as electrons.

• Never has more than 1.5 times as many neutrons as protons; atoms may be radioactive.

Imagine that Rutherford discovered that during his gold foil experiment, ten percent of the alpha particles (helium cations) went through the gold foil in his team’s gold foil experiment and the rest were deflected at various angles (this is not what actually happened). Which model described below is consistent with this hypothetical result?

• The atom has a cubic shape with no space between atoms

• The atom is mostly empty space.

• Atoms are spherical and closely packed, with small amounts of space between atoms.

• Atoms are shaped like thin donuts, with very large spaces, or holes, inside each one.

What is the predicted chemical behavior of a nitrogen atom?

• A nitrogen atom is stable. it will neither lose nor gain electrons

• A nitrogen atom will gain three electrons

• A nitrogen atom will lose three electrons

• A nitrogen atom will gain six electrons to form three chemical bonds

• A nitrogen atom will gain one electron

Two atoms or ions are said to be isoelectronic when they have the same total number of electrons.Which two atoms or ions are isoelectronic?

• The sodium cation and magnesium

• The oxygen dianion and carbon

• Neon and argon

• The magnesium dication and neon

• Hydrogen and seaborgium

Which ion has 50 electrons? 

• Sn

Igor Mikhailovskij provided excellent evidence that atoms exist when he published __________.

• A genuine image of a molecule with visible bonds

• A genuine image of a neutron visible within a carbon atom, where the nucleus is shown in black and the neutrons within it visible as a blue region

• A genuine detailed image of an atom with a visible electron-rich region

• A genuine of two atoms of hydrogen bonded together wih visible electrons between them.

Copper is made up of two isotopes, Cu-63 (62.9296 amu) and Cu-65 (64.9278 amu). Given copper's average atomic mass of 63.546 amu, what is the percent abundance of each isotope?Hint: let x be the abundance of the first isotope, and since they total 1, let 1-x be the abundance of the second isotope. Other methods can be used to answer this problems as well.Please choose the closest answer.

• 69.15% Cu-63, and 30.85% Cu-65

• 69.40% Cu-63, and 30.60% Cu-65

• 68.20 % Cu-63, and 31.80% Cu-65

• 31.80% Cu-63, and 68.20% Cu-65