Systems Biology Homework 3 …



Name Date Period

CP Biology 2015-16

PRACTICE PACKET

UNIT 2A:

Basic Chemistry

HW #1: Periodic Table

Use the following terms to fill in the blanks for questions 1-9:

protons mass number neutrons energy levels nucleus symbol electrons atomic number

1) The large letter(s) that represent each element is called a symbol

2) The number of protons in the nucleus of an atom is the same as the a) _ atomic number __, and

b) electrons.

The periodic table is arranged in general order of increasing a) ___ atomic number__,

b) __ mass number ______ and, c) ___ # electrons (energy levels) ________.

3) Each element in the table has a different a) _ atomic number ____, b) # protons

c) symbol ________, and d) _ mass number _________.

Complete the diagram by labeling all the parts.

5) electron (valence)

6) nucleus

Made up of 7) protons and 8) neutrons

9) energy levels in the electron cloud

12) Complete the following table by placing a check in each box that makes the statement true:

|Characteristic |Proton |Neutron |Electron |

|Does not have an electrical charge | |X | |

|Found in the nucleus |X |X | |

|Positively charged |X | | |

|Moves in energy levels | | |X |

|Negatively charged | | |X |

|Has nearly no mass | | |X |

|Added together to make the mass number or atomic mass (weight) |X |X | |

HW #2: Atomic Structure

You will become more familiar with the atomic structure of common elements by completing the chart below. For each element, you have been given enough information to fill in all the blanks.

|Element |Symbol |Atomic Number |Mass Number |Number of Protons |Numbers of Neutrons |Number of Electrons | |

|Hydrogen |H |1 |1 |1 |1 |R |1 |

| | | | | |Duet rule | | |

|Aluminum |Al |13 |13 |3 |5 |R |X |

|Carbon |C |6 |6 |4 |4 |R |4 |

|Sodium |Na |11 |11 |1 |7 |R |X |

|Neon |Ne |10 |10 |8 |0 |NR |0 |

|Oxygen |O |8 |8 |6 |2 |R |2 |

|Nitrogen |N |7 |7 |5 |3 |R |3 |

|Phosphorus |P |15 |15 |5 |3 |R |3 |

List the most common elements in living things:____C__, __H____, ___O___, ___N___, __P______

Are these elements reactive or non-reactive? ______REACTIVE____________

HW #4: Electrons and the Reactivity of Atoms

Directions: Place the answer to the following questions on the line provided.

___D___1. Energy levels are:

a. the definite locations of electrons c. the charge of protons

b. the charge of atoms d. the probable locations of electrons

__B___2. If an atom is reactive, how does it become stable?

a. join a water molecule

b. form bonds with other reactive atoms

c. form energy levels with other subatomic particles

d. join the nuclei of other atoms.

Directions: Smiley Cyrus was a student at Livingston High School. Below are her drawings of different atoms.

Check Smiley Cyrus’s atoms and correct any mistakes that she made.

* P=protons N=neutrons E= Electrons = electrons in energy levels

Aluminum Potassium Lithium

Add 3 e- should be 19 e- total 3 e-

Circle the atoms below that are reactive.

Al K Li

How many electrons will the following need to be stable? Write the number on the line provided.

Al ____5___ K ___7_____ Li ___7_____

1) Is one atom of carbon stable?________no________ Why or why not?___with only four electrons in its outer shell one carbon atom needs four more electrons to be stable (fulfill the octet rule)____________

2) What is the purpose of bonding? _In order to allow an atom to become stable (by sharing electrons to fill its vacancies – valence level)_________________________________________________

3) How many electrons will an atom of carbon share with another atom in order to become stable? __4___

4) List three different types of bonds that can form between atoms?

a)____covalent____, b) ___ionic_________ and c) __hydrogen___________

5) A __chemical formula___shows the types and numbers of atoms in a compound. For example, H2O indicates that one atom of oxygen has formed with two atoms of hydrogen.

The ____subscript__ indicates how many atoms of the preceding element are needed in the final molecule.

A __coefficient____ indicates how many molecules of each compound are present. In order to determine the number of atoms in a formula with a coefficient, multiply the coefficient by the _subscript___. When the coefficient for a molecule is not indicated, that coefficient is the number one (example: CO2 indicates one molecule of carbon dioxide). When the subscript for an atom is not indicated, that subscript is the number one (example: the O in H2O).

Complete in the following chart:

|Chemical Formula |Numbers and types of atoms in the compound |

|H2O |Two hydrogen atoms and one oxygen atom. |

|CaCO3 |One calcium atom, one carbon atom, 3 oxygen atoms |

|3H2O | 6 hydrogen atoms, three oxygen atom |

|4H2SO4 |8 hydrogen atoms, 4 sulfur atoms, 16 oxygen atoms |

Directions for drawing structural formulas:

A structural formula is a drawing of the atoms in a compound and the number of bonds between atoms. The short lines in a structural formula represent a bond that has formed between two atoms. A single bond is represented by a single line (-). A double bond is shown with two lines (=). A triple bond would contain 3 lines (().

Example H2O or water :

In one water molecule, there _2__ atom(s) of hydrogen and _1___ atom(s) of oxygen.

H=Hydrogen—Has one electron and one vacancy in the first energy level. So, it needs _1__ bond(s) to be stable.

O=Oxygen—Has 2 electrons in the first level and 6 in the second level. So, it needs _2_ bond(s) to be stable.

The only way to represent this is to draw:

|H O H |In this way, the two atoms of hydrogen are bonded with one atom of oxygen. The |

| |hydrogen atoms each have one bond and the oxygen atom has two bonds. |

Try these examples:

Draw the structural formulas for the following compounds:

|H2 |CH4 |

|# bonds needed by hydrogen? _____1______ |# bonds needed by carbon? ___4___ hydrogen? __1__ |

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|O2 |HCl |

|# bonds needed by oxygen? ____2____ |# bonds needed by hydrogen? ___1____ Cl? ___1__ |

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|N2 |PCl3 |

|# bonds needed by nitrogen ___3_____ |# bonds needed by phosphorus? ___3___ Cl?____1__ |

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|HCN (Hydrogen cyanide) |H2O |

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HW #6 Counting Atoms

Calculate how many atoms of each element are present in the following compounds.

1. NaHCO3 Na-1

H -1

C -1

O -3

2. C2H4O2 C-2

H-4

O-2

3. 3H3 PO4 H- 9

P-3

O-12

4. 2H2SO4 H-4

S-2

O-8

5. C6H12O6 C-6

H-12

O-6

6. 4CaCO3 Ca-4

C-4

O-12

:***7. Mg(OH)2 Mg-1

O-2

H-2

***8. (NH4)3PO4 N-3

H-12

P-1

O-4

HW #7: Recognizing Balanced Equations

| |EQUATION | BALANCED? (Y/N) |

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|A. |H2 + O2 --> H2O2 |Y |

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|B. |H2O2 --> H2O + O2 |N |

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|C. |4Na + O2 --> 2Na2O |Y |

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|D. |N2 + H2 --> NH3 |N |

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|E. |P4 + O2 --> P4O10 |N |

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|F. |Fe + H2O --> Fe3O4 + H2 |N |

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|G. |C + 2H2 --> CH4 |Y |

| |Na2SO4 + CaCl2 --> CaSO4 + NaCl | |

|H. | |N |

| |C2H6 + O2 --> CO2 + H2O | |

|I. | |N |

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|J. |2Al2O3 --> 4Al + 3O2 |Y |

HW #8: Balancing Equations

Answer the following questions. Use complete sentences when given one or more lines to respond.

1) What is the difference between reactants and products in a chemical equation?

_____reactants are the compounds that recombine____________________________

_____products are the result of the recombination of reactants____________________________

2) Which number indicates the number of atoms of each element in a molecule of a substance?

_____the subscript indicates the number of atoms of each element in a molecule of a substance _____

3) Which number indicates the number of molecules?

_____the coefficient indicates the number of molecules_________

4) Why must chemical equations always balance?

_____Chemical equations are the mathematical representation of chemical reactions, and matter (the atoms) is not created or destroyed in the reaction. Therefore the number of atoms does not change, even though they have been rearranged_______.

5) Based on the Law of Conservation of Matter, which of the following equations is balanced?

• Put a check on the line provided if the equation is balanced.

• Extension: If the equation is NOT balanced, then rewrite a correctly balanced equation below it.

a) H2 + Cl2 ( 2HCl (

b) 2H2O2 ( 2H2O + O2 (

c) N2 + H2 ( NH3 N2 + 3H2 ( 2NH3

d) Fe + 3O2 ( Fe2O3 4Fe + 3O2 ( 2Fe2O3

e) C6H12O6 + O2 ( CO2 + H2O C6H12O6 + 6O2 ( 6CO2 + 6H2O

KEY to this graphic organizer is on the next page!!!

*SEE KEY on next page*

[pic]

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1

octet

13 P

14 E N

3 E

7 N

20 P

20 N

19 P not 20 P in the nucleus

3P & 4 N in the nucleus, not 7 E

14 N in the nucleus, not 14 E

H H

H

H C H

H

O O

H Cl

N N

Cl P Cl

Cl

H C N

H H

O

7

7

Protons

Neutrons

ATOM

Electrons

Atomic Number

Mass Number

Symbol

Valence Electrons

Octet Rule

Covalent Bond

Molecule

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