Name:  _________________________________  Class  Color:  _______________  Date:  ____________        I

INTRODUCTION TO CHEMISTRY: Atoms, Molecules, & Chemical Reactions Directions: Read & highlight key points. What is your body made of? Your first thought might be that it is made up of different organs—such as your heart, lungs, and stomach—that work together to keep your body going. Or you might zoom in a level and say that your body is made up of many different types of cells. However, at the most basic level, your body—and, in fact, all of life, as well as the nonliving world—is made up of atoms, often organized into larger structures called molecules. Humans are made up of roughly 7,000,000,000,000,000,000,000,000,000 atoms (7 billion billion billion!!), so you'll probably want to know the basics as you begin to explore the world of chemistry!

An atom is the smallest unit of matter that retains all of the chemical properties of an element. For example, a gold brick is simply a very large number of gold atoms molded into the shape of a brick, with small amounts of other elements. Gold atoms cannot be broken down into anything smaller while still retaining the properties of gold. A gold atom gets its properties from the tiny subatomic particles it's made up of (protons, neutrons, & electrons).    

Structure  of  Atoms:    

1. What  is  an  atom?  ________________________________________________________________________________________________________________________________  

2. What  is  in  the  nucleus  of  an  atom?  _____________  &  _______________  3. What  moves  in  circles  around  the  nucleus  of  an  atom?  

_____________________  4. Based  on  the  images,  what  is  the  charge  of  a(n)…  

a. Electron?  ________________  b. Proton?  ________________  c. Based  on  the  fact  that  it  is  not  shown  below,  what  

is  likely  the  charge  of  a  neutron?    (Hint:  Neutron  means  “neutral”)  __________    

5. What  do  the  hydrogen  and  oxygen  atoms  have  in  common?  Similarities:      

6. What  is  different  about  the  hydrogen  and  oxygen  atom?    Differences:  

                       

Name:  _________________________________  Class  Color:  _______________  Date:  ____________        I  Molecules:  A  molecule  is  a  group  of  atoms  bonded  together.  If  you  combine  two  hydrogen  atoms  and  one  oxygen  atom,  you  get  a  water  molecule,  known  as  H20.  The  small  numbers  are  called  subscripts  and  represent  the  number  of  atoms  in  a  molecule.  (Note:  If  there  is  no  subscript,  there  is  only  one  atom  present.)    7.  List  the  number  of  atoms  in  each  of  the  following,  based  on  their  molecular  formula:    Molecule  Name   Function   Molecular  Formula   #  of  Atoms  

 Formaldehyde  

Chemical  used  to  preserve  dead  bodies;  such  as  for  a  funeral  

 CH2O  

Carbon  (C)  =  _______  

Hydrogen  (H)  =  ______  

Oxygen  (O)  =  ______  

 Hydrogen  Cyanide  

Extremely  poisonous  chemical  compound;  often  used  to  kill  villains  in  movies  

 HCN  

Hydrogen  (H)  =  ______  

Carbon  (C)  =  ______  

Nitrogen  (N)  =  ______  

 Glucose  

Another  words  for  sugar;  the  body  breaks  this  down  to  create  

energy  

 C6H12O6  

Carbon  (C)  =  _______  

Hydrogen  (H)  =  ______  

Oxygen  (O)  =  _______  

 Chemical  Reactions:  A  chemical  reaction  is  when  the  atoms  of  molecules  are  rearranged  to  create  new  molecules.  This  process  cannot  be  undone.  A  primary  example  of  this  is  the  reaction  of  hydrogen  peroxide    (a  molecule  with  negative  effects  on  the  body,  produced  as  a  byproduct  in  our  cells)  and  the  enzyme  catalase.  Enzymes  are  proteins  that  help  speed  up  chemical  reactions.  If  catalase  was  not  available,  the  hydrogen  peroxide  would  not  be  broken  down  fast  enough,  and  we  would  die.      8.  Looking  at  the  image,  which  two  molecules  does  catalase  break  hydrogen  peroxide  into?  (Write  their  names,  not  their  formula.)    H2O2  à  _________________  +  __________________     Look  at  the  catalase  demo  your  teacher  will  show  you  up  front...      9.  When  the  potato  (containing  catalase)  is  added  to  the  hydrogen  peroxide,  what  do  you  expect  will  

happen?  _________________________________________________________________  

 10.  [WATCH  DEMO  1  à]    What  happened?  _________________________________  Why?  ____________________________    11.  Now  what  do  you  think  will  happen  if  you  remove  the  first  piece  of  potato  and  put  a  new  piece  of  

potato  into  the  same  solution?  __________________________________________________________________________________  

 12.  [VIEW  DEMO  2  à  ]  What  happened?  ____________________________________    13.  Why  did  this  occur?  (What  is  that  liquid  left  behind??)  ___________________________________________  

Name:  _________________________________  Class  Color:  _______________  Date:  ____________        I Chemical  Equations:    

• Look  at  the  chemical  equation  of  the  catalase  reaction  below.  • The  small  numbers  are  the  subscripts,  which  is  the  number  of  atoms  present.  (Note:  If  there  is  

no  subscript,  there  is  only  one  atom  present).  • The  big  numbers  are  called  coefficients,  and  they  represent  the  amount  of  times  

you  should  multiply  the  atom.  (Note:  You  multiply  coefficients  times  ALL  atoms  in  the  molecule.)  • If  an  atom  has  both  a  subscript  and  a  coefficient,  you  multiply  (x)  them  together.    

 PRODUCTS:           REACTANTS:  

               14.  Continue  filling  in  this  chart  below,  using  the  equation  above.    

#  of  atoms  in  Products   #  of  atoms  in  Reactants  Hydrogen     Hydrogen    Oxygen     Oxygen   (2  x  1  =  2)  +  2  =  4  

 15.  What  do  you  notice  about  the  number  of  atoms  in  the  products  and  the  number  of  atoms  

in  the  reactants?  ___________________________________________    

Conservation  of  Mass:  

This  is  known  at  the  Law  of  Conservation  of  Mass,  which  is  the  idea  that  matter  (anything  that  has  mass  and  takes  up  space)  cannot  be  created  or  destroyed.  That  means  that  even  when  atoms  are  rearranged,  they  do  not  disappear.  There  must  be  the  same  number  of  atoms  on  each  side  of  a  chemical  equation.  If  initially  the  sides  are  not  even,  you  must  add  coefficients  to  the  correct  molecule  to  balance  the  equation.    

Using  the  resources  provided  by  your  teacher,  demonstrate  the  catalase  reaction...      16.  Start  by  creating  2  molecules  of  hydrogen  peroxide  (H202)  and  show  your  teacher.    17.  Then,  using  those  exact  same  atoms,  take  apart  your  molecules  and  rearrange    the  atoms  to  create  the  products  of  the  reaction-­‐  water  (H2O)  and  oxygen  (O2).    

 

2  Hydrogen  Peroxide  molecules            à                                  2  Water  molecules     +            1  Oxygen  molecule                        2  H2O2                                                        2  H2O                                                        O2  

Note  the  double  bond  between  the  two  oxygen  

atoms!  Catalase