View
4
Download
0
Category
Preview:
Citation preview
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
Recommended