Compounds & Molecules
1
1
Which of the following statements best describes pure substances
A. Pure substances consist of substances that have been combined through physical processes or changes
B. Pure substances consist of substances that have been separated through physical processes
C. Pure substances consist of elements, compounds, and molecules
D. Pure substances consist of solutions, suspensions, and colloids
C
How can you separate the compound that makes up sand into its elements?
Chemical Changes
Lactose Formula (C12H22O11). What can we conclude about lactose based on the formula
A. Some people may be allergic to lactose
B. A lactose molecule contains 12 atoms of carbon
C. Lactose is a key ingredient in many medicines
D. Lactose has a melting point of about 203°C
B. A lactose molecule contains 12 atoms of carbon
What is a Base
When a substance has extra hydroxide ions (OH- ) then it is a base.
List Some Diatomic Molecules
Hydrogen H2
Nitrogen N2
Oxygen O2
Fluorine F2
Chlorine Cl2
Bromine Br2
Iodine I2
What type of substance is always made up of a single type of atom
Element
Which of these substances is a compound? The chemical symbol/formula of each are listed in parentheses
A. Chlorine (Cl) B. Ammonia (NH3) C. Uranium (U) D. Nitrogen (N)
Which is true about each group of atoms that makes up a compound
Compound Groups are Identical
What Are Bases Also Called
Alkalis or Alkaline
What is a Compound
- Are pure substances that are composed of multiple types of elements (2 or more), chemically bonded to one another
- Compounds can only be broken down by chemical reactions
Atoms combine in many different ways to form different substances. Iron is an element. Brass is not an element, instead brass is a combination of two elements. What is the difference between iron and brass
Brass is a compound, iron is not
Sucrose is another name for table sugar. Sucrose is a compound made from the elements carbon, hydrogen, and oxygen. Which statement best describes the properties of sucrose?
A. The properties of sucrose are similar to properties of carbon
B. The properties of sucrose are similar to properties of oxygen
C. The properties of sucrose are similar to the properties of hydrogen
D. The properties of sucrose are different from the properties of each the elements sucrose contains
Define Element
- Are the simplest kind of pure substance
- Consists of only one kind of atom
-Cannot be broken down into a simpler type of matter by either physical or chemical means, and
- Can exist as either atoms (e.g. argon) or molecules (e.g., nitrogen).
The label on a chemical in a science laboratory reads, “Strong Acid.” Based on this label, what can a student best determine about the chemical?
A. It has a low pH
B. It is a clear liquid
C. It has a high density
D. It has a low melting point
What is Mixture
A mixture is something that CAN be broken down into simpler materials using physical methods
In which state of matter is the connection between the molecules the strongest
A Solid
What is the value of a pH of a substance that is neutral
7
Define Molecule
- A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together.
- Can be chemically broken down
Physical Properties of Acid
Acids taste sour (e.g. vinegar, lemon juice).
Acids are harmful to living cells.
Aqueous solutions of all acids contain hydrogen ions.
]Acid turns blue litmus red.
Strong acids are corrosive.
Name the 2 Types of Mixtures
Homogenous and Heterogenous
Two white powders were mixed together. A chemical reaction occurred, and a yellow powder was formed. What is the relationship between the yellow powder and the white powders
The yellow powder is made up of the same kinds of atoms as the white powders creating a new molecule
What is an Acid
Any substance that has extra Hydrogen Ions is an acid. The more Hydroger (H+) Ions the more acidic.
What is Diatomic Molecule
A group of 2 or more atom.
Physically Properties of Bases
Alkalis are taste bitter
Strong alkalis are corrosive.
Aqueous solutions of all alkalis contain hydroxide ion.
Alkalis turns red litmus blue.
Soapy touch.
DAILY DOUBLE
Define Homogeneous and Heterogenous Mixtures
Homogeneous Mixtures : The parts are distributed evenly. Salt Water, Syrup, Air
Heterogenous Mixtures: The parts are distributed unevenly. Spaghetti