U1(pt.1): Atomic Structure and the Periodic Table

Chlorine is the atomic number 17 in the periodic table of elements. What information does the atomic number give you about the element chlorine? 

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• An atom of chlorine has 17 protons and neutrons combined.

• An atom of chlorine has 17 protons.

• An atom of chlorine has 17 protons and 17 neutrons.

• Chlorine atoms have 17 of each of the three subatomic particles, protons, neutrons, and electrons.

An Aluminum atom has an atomic number of 13 and an atomic mass of 27. Based on that knowledge, which of these statements is NOT true concerning the atomic structure of aluminum? 

• Aluminum has 13 neutrons.

  
  

• Aluminum has 14 neutrons.

• Aluminum has 13 Protons.

• The number of protons equals the number of electrons.

Based on your understanding of the periodic table, which element has the greatest number of electrons?

• Uranium (U)

  
  

• Sodium (Na)

  
  

• Selenium (Se)

  
  

• Polonium (Po)

  
  

Atom A has an atomic number of 19 and mass number of 40. Atom B has an atomic number of 20 and a mass number of 40. Which of these is an accurate statement?

• Atom A has more protons than Atom B.

  
  

• Atom A has one less proton and one more neutron than Atom B.

  
  

• Atom A has an extra nucleon compared to Atom B.

  
  

• Atom A has one more proton and one more electron than Atom B.

  
  

An atom with an atomic number of 12 and a mass number of 25 can best be described by which of these?

• An atom that contains 12 protons and 13 neutrons.

  
  

• An atom that contains 13 protons and 12 neutrons.

  
  

• An atom that contains 12 protons and 25 neutrons.

  
  

• An atom that contains 25 protons and 12 neutrons.

  
  

Using the periodic table and your knowledge of atomic structure. Cobalt (Co) and nickel (Ni) have almost identical atomic mass numbers. Comparing the typical nickel and cobalt atoms, which statement best describes the atoms?

• Nickel has one more neutron.

• Cobalt has one less proton.

• Both atoms will have the same number of protons.

• Both atoms will have the same number of neutrons.

Which statement best describes the difference(s) between atoms and molecules?

• Atoms are the most basic units of an element whereas molecules are atoms that are chemically bonded together.

  
  

• Atoms are the most basic units of an element that have charges whereas molecules are neutral substances that consist of atoms chemically bonded together.

  
  

• Atoms are made up of protons, neutrons, and electrons but molecules do not consist of these subatomic particles.

  
  

• Atoms are made up of molecules whereas molecules are made up of ions.

  
  

Consider the elements in this family (group) of the periodic table. Because they are in the same family, what can you predict about these elements?

• They are all about the same mass.

  
  

• They are chemically reactive in a similar way.

  
  

• The size of the atom decreases as you go down the column.

  
  

• The elements change from metals to nonmetals as go down the column.

  
  

Consider this row in the periodic table of elements. As we move from left to right, across the row, the elements

• change from nonmetals to metals.

  
  

• change from metals to nonmetals.

  
  

• start as gases but end as solids.

  
  

• show a decrease in atomic mass number.

  
  

The majority of the mass of the atom is located in the _______.

• nucleus

• core electrons

• pions and quarks

• valence electrons