11/27/2015 PhSci Ch 4 17 Questions 1 4B = Section 2 The Structure of Atoms p (Question will be on 4B quiz, too.) Physical Science Curriculum

11/27/2015 PhSci Ch 4 17 Questions 19 slides2 Give the relative masses of protons, neutrons & electrons Protons & neutrons have about the same mass; Protons & neutrons have about the same mass; Electrons are over 1, 000 times smaller (in mass than protons & neutrons).  Electrons are over 1, 000 times smaller (in mass than protons & neutrons). 

11/27/2015 PhSci Ch 4 17 Questions 3 Give what defines each element The number of protons  The number of protons 

11/27/2015 PhSci Ch 4 17 Questions 4 Explain why most (unreacted) atoms do not have an overall charge if they are made of charged particles Most atoms have an equal number Most atoms have an equal number of protons and electrons of protons and electrons whose charges exactly cancel.  whose charges exactly cancel. 

11/27/2015 PhSci Ch 4 17 Questions 5 Define ion an atom an atom who has gained or lost an electron who has gained or lost an electron and therefore (  ) is charged.  and therefore (  ) is charged. 

11/27/2015 PhSci Ch 4 17 Questions 6 Explain what holds atoms together Attractions Attractions between the opposite charges between the opposite charges of protons and electrons  of protons and electrons 

11/27/2015 PhSci Ch 4 17 Questions 7 Explain how different elements have their own unique properties The atoms The atoms of each type of element of each type of element have their own different structure  have their own different structure 

11/27/2015 PhSci Ch 4 17 Questions 8 Define atomic number how many protons are in an atom  how many protons are in an atom 

11/27/2015 PhSci Ch 4 17 Questions 9 Give the largest naturally occurring element and its atomic number Uranium, Uranium, 92  92 

11/27/2015 PhSci Ch 4 17 Questions 10 Define mass number Tells the number of protons Tells the number of protons plus the number of neutrons plus the number of neutrons in an atom.  in an atom. 

11/27/2015 PhSci Ch 4 17 Questions 11 Define isotope An atom An atom that has the same number of protons that has the same number of protons but a different number of neutrons.  but a different number of neutrons. 

11/27/2015 PhSci Ch 4 17 Questions 12 Define radioisotopes Unstable isotopes Unstable isotopes which emits radiation which emits radiation and decays into stable forms and decays into stable forms (this might take a long time and many steps).  (this might take a long time and many steps). 

11/27/2015 PhSci Ch 4 17 Questions 13 Define unified atomic mass unit A quantity used to measure the mass of atoms A quantity used to measure the mass of atoms (which is equal to 1/12 of a carbon- 12 atom) (which is equal to 1/12 of a carbon- 12 atom) And is abbreviated u. (Sometimes called an amu)  And is abbreviated u. (Sometimes called an amu) 

11/27/2015 PhSci Ch 4 17 Questions 14 Define average atomic mass average of the mass average of the mass of an element’s atoms found in nature of an element’s atoms found in nature where common isotopes are more important  where common isotopes are more important 

11/27/2015 PhSci Ch 4 14 Questions 18 slides 15 Define valence electrons Electrons in the outer energy level of an atom  Electrons in the outer energy level of an atom 

11/27/2015 PhSci Ch 4 17 Questions 16 *** Using a periodic table, give the # of protons, neutrons, & electrons of various atoms

11/27/2015 PhSci Ch 4 17 Questions 17 *** Calculate atomic number & mass number

11/27/2015 PhSci Ch 4 17 Questions 18 *** Write isotopes using the forms given on p 124 (Fig 5 and in the reading)

11/27/2015 PhSci Ch 4 17 Questions 19 The end The end