BASIC CHEMISTRY – Part 2
Name:
Date:
Pd:
PART 1: MIXTURES:
Fill in the blanks from the information provided on the presentation.


A mixture is two or more substances blended together (not bonded).
Each substance in a mixture keeps all of its chemical and physical properties.


Mixtures, unlike compounds, can be separated into their individual substances by physical means.
Example: salt and water can be separated by evaporation.


A solution is a mixture of two or more substances, one dissolved in another.
Two parts of a solution are the solute and the solvent.

Solute – substance being dissolved
Examples: sugar, salt
Solvent – substance doing the dissolving
Example: water


A solution becomes saturated when the solvent holds all the solute that it can. It can no longer
dissolve solute.

Suspensions are a mixture of particles scattered throughout another. The particles do not
dissolve. Examples: clouds, dust, fog, smoke, mud, blood
Reflect:
1. Give another example of solutions including the solute and solvent.
Vinegar and Calcium Carbonate, etc…
2. Can solutions be separated by chemical means?
Perhaps, but will still involve physical separation as well
PART 2: COMPOUNDS
 Compounds are two or more elements chemically joined by bonds.
 They are represented by chemical formulas.
 Properties of compounds are usually different than the atoms.
Example: Hydrogen(gas) + Oxygen(gas) = Water (liquid)
Example: Iron + Oxygen = Rust
 Compounds can be separated into their elements only if the chemical bonds are broken. This can
be done by chemical means (chemical reaction)
 A molecule is the smallest part of a compound—like water—that has all the properties of the
compound.
PART 3: REVIEW COMPOUNDS AND ELEMENTS
Write “E” for element or “C” for compound or B for BOTH for each description below:
1. __C__ Two or more elements combined
7. __C__ Water (H2O)
2. __E__ Made up of one type of atom
8. __B__ Smallest unit of a substance
3. __E__ Cannot be chemically broken down
9. __E__ Smallest unit of matter
4. __C__ Table Salt (NaCl)
10. __B__ Units of matter
5. __E__ Sodium (Na)
11. __E__ Hydrogen (H)
6. __C__ Glucose
12. __C__ Can be broken down chemically
PART 4: FORMATION OF CHEMICAL BONDS


A covalent bond is a bond formed when atoms share electrons to form a compound.
Strong physical bond
hydrogen
oxygen
2 covalent bonds
hydrogen
H2O Molecule


An ionic bond is formed by the transfer of electrons from one atom to another.
It is a weak electrical attraction, not a physical bond.
Example: table salt (NaCl)
Before
11 p+
11 e0
After
11 p+
10 e+1


Sodium
(+)
Chlorine
(-)
Before
17 p+
17 e0
After
17 p+
18 e-1
Instead of being neutral, atoms of sodium and chlorine making up salt become charged.
Ions are charged atoms that have gained or lost one or more electrons.
BASIC CHEMISTRY – Part 2 (page 2)
Name: Answer Key
Date:
Pd:
PART 5: CHEMICAL REACTIONS

A chemical reaction is the process of breaking down existing chemical bonds of compound and
forming new bonds.


Elements combine in ways that cause their atoms to be stable.
The energy required to start a chemical reaction is activation energy and the most common form
of this energy is heat.


A reaction that gives off more energy than it uses up is an exothermic reaction.
A reaction that gives off less energy than it uses up is an endothermic reaction.

Living things need a constant supply of energy from food because all cells use more energy than
they produce.

Example reactions:
Photosynthesis
Water + Carbon Dioxide  Glucose (Sugar) + Oxygen.
H2O +
CO2

C6H12O6
+ 6O2
Respiration (Breathing)
Oxygen + food(glucose)  water + carbon dioxide
6O2 +
C6H12O6  H2O +
CO2
Rusting, Burning, Digestion, etc…
Reactants are on the left.
Products are on the right.
PART 6: QUESTIONS:
1. List and describe the major kinds of chemicals.
Mixture – two or more blended substances
Solution – A solute with a solvent dissolved in it
Compound – two or more bonded substances
2. What is the difference between an ionic and covalent bond?
Covalent bonds are strong physical bonds where atoms share electrons.
Ionic bonds are weak electrical bonds where atoms transfer electrons.
3. Are mixtures formed during a chemical reaction? Why or why not?
Mixtures are not formed during a chemical reaction because no bonds are being broken or
formed.
4. How are mixtures, compounds, and chemical reactions important for living things?
BASIC CHEMISTRY – Part 2
Name: Answer Key
Date:
Pd:
PART 1: MIXTURES:
Fill in the blanks from the information provided on the presentation.


A mixture is two or more substances blended together (not bonded).
Each substance in a mixture keeps all of its chemical and physical properties.


Mixtures, unlike compounds, can be separated into their individual substances by physical means.
Example: salt and water can be separated by evaporation.


A solution is a mixture of two or more substances, one dissolved in another.
Two parts of a solution are the solute and the solvent.

Solute – substance being dissolved
Examples: sugar, salt
Solvent – substance doing the dissolving
Example: water


A solution becomes saturated when the solvent holds all the solute that it can. It can no longer
dissolve solute.

Suspensions are a mixture of particles scattered throughout another. The particles do not
dissolve. Examples: clouds, dust, fog, smoke, mud, blood
Reflect:
3. Give another example of solutions including the solute and solvent.
Vinegar and Calcium Carbonate, etc…
4. Can solutions be separated by chemical means?
Perhaps, but will still involve physical separation as well
PART 2: COMPOUNDS
 Compounds are two or more elements chemically joined by bonds.
 They are represented by chemical formulas.
 Properties of compounds are usually different than the atoms.
Example: Hydrogen(gas) + Oxygen(gas) = Water (liquid)
Example: Iron + Oxygen = Rust
 Compounds can be separated into their elements only if the chemical bonds are broken. This can
be done by chemical means (chemical reaction)
 A molecule is the smallest part of a compound—like water—that has all the properties of the
compound.
PART 3: REVIEW COMPOUNDS AND ELEMENTS
Write “E” for element or “C” for compound or B for BOTH for each description below:
13. __C__ Two or more elements combined
19. __C__ Water (H2O)
14. __E__ Made up of one type of atom
20. __B__ Smallest unit of a substance
15. __E__ Cannot be chemically broken down
21. __E__ Smallest unit of matter
16. __C__ Table Salt (NaCl)
22. __B__ Units of matter
17. __E__ Sodium (Na)
23. __E__ Hydrogen (H)
18. __C__ Glucose
24. __C__ Can be broken down chemically
PART 4: FORMATION OF CHEMICAL BONDS


A covalent bond is a bond formed when atoms share electrons to form a compound.
Strong physical bond
hydrogen
8
8
oxygen
2 covalent bonds
hydrogen
H2O Molecule


An ionic bond is formed by the transfer of electrons from one atom to another.
It is a weak electrical attraction, not a physical bond.
Example: table salt (NaCl)
Sodium
Before
11 p+
11 e0
After
11 p+
10 e+1


Chlorine
Before
17 p+
17 e0
Transfer
(+)
(-)
After
17 p+
18 e-1
Instead of being neutral, atoms of sodium and chlorine making up salt become charged.
Ions are charged atoms that have gained or lost one or more electrons.
BASIC CHEMISTRY – Part 2 (page 2)
Name: Answer Key
Date:
Pd:
PART 5: CHEMICAL REACTIONS

A chemical reaction is the process of breaking down existing chemical bonds of compound and
forming new bonds.


Elements combine in ways that cause their atoms to be stable.
The energy required to start a chemical reaction is activation energy and the most common form
of this energy is heat.


A reaction that gives off more energy than it uses up is an exothermic reaction.
A reaction that gives off less energy than it uses up is an endothermic reaction.

Living things need a constant supply of energy from food because all cells use more energy than
they produce.

Example reactions:
Photosynthesis
Water + Carbon Dioxide  Glucose (Sugar) + Oxygen.
H2O +
CO2

C6H12O6
+ 6O2
Respiration (Breathing)
Oxygen + food(glucose)  water + carbon dioxide
6O2 +
C6H12O6  H2O +
CO2
Rusting, Burning, Digestion, etc…
Reactants are on the left.
Products are on the right.
PART 6: QUESTIONS:
5. List and describe the major kinds of chemicals.
Mixture – two or more blended substances
Solution – A solute with a solvent dissolved in it
Compound – two or more bonded substances
6. What is the difference between an ionic and covalent bond?
Covalent bonds are strong physical bonds where atoms share electrons.
Ionic bonds are weak electrical bonds where atoms transfer electrons.
7. Are mixtures formed during a chemical reaction? Why or why not?
Mixtures are not formed during a chemical reaction because no bonds are being broken or
formed.
8. How are mixtures, compounds, and chemical reactions important for living things?