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WorksheetsChemistry Review (EL #4)
Total questions: 32
Worksheet time: 26mins
Which of the following is a compound?
Ne
Na
NaHCO₃
N
Is C₂H₄O₂ a compound or element?
Compound
Element
Which of the following is the correct balanced equation for the decomposition of Mercury(II) oxide?
HgO → Hg + 2O2
2HgO → Hg + O₂
HgO → 2HgO₂
2HgO → 2Hg + O₂
What is the chemical formula for the molecule represented in the image?
HO
H2O
H2O2
HO2
Where does a coefficient belong in a chemical equation (if needed)?
In the middle of a compound or formula as needed.
In the front of a formula or compound as needed.
It can be placed anywhere in a chemical equation.
It goes behind a chemical formula as needed.
Balance the equation: ( Na + O2 -> Na2O ) When balanced, how many total atoms are in the reactants?
7
9
6
3
Ammonia, ( NH3 ), is an example of a(n):
Mixture
Atom
Element
Compound
What does the image represent?
Atom
Molecule
Compound
Heterogeneous mixture
What does the image represent?
Atom
Molecule
Compound
Element
What does the image represent?
Atom
Molecule
Compound
Homogeneous mixture
How would you classify the mixture shown in the bowl?
Homogeneous mixture
Heterogeneous mixture
Compound
Molecule
How would you classify the mixture shown in the cup?
Homogeneous mixture
Heterogeneous mixture
Compound
Molecule
In the chemical formula 4CO₂, what does the number 4 represent?
coefficient indicating the number of molecules needed
subscript indicating the number of molecules needed
atomic number indicating the number of molecules needed
superscript indicating the number of molecules needed
In the chemical formula 4CO₂, what does the number 2 represent?
The number of molecules
The subscript indicating the number of oxygen atoms
The atomic number of carbon
The coefficient
Select all of the elements that are in the following chemical formula: NaHCO3?
Sulphur
Hydrogen
Sodium
Oxygen
Carbon
What math operation do you use to find out how many total number of oxygen atoms are in the chemical formula 4H2O2 ?
Subtraction
Addition
Multiplication
Division
In the Law of Conservation of Mass, the total mass of the ________ is always equal to the total mass of the ________.
reactants, products
reactants, balanced
reactants, production
reacting, production
When a new capital letter is present in a chemical formula or compound, what does that represent?
There is a new element in the chemical formula
That is the start of a new compound
Nothing. It is just another letter
It indicates a chemical reaction has occurred
How many carbon atoms are present in the chemical formula 2C12H22012?
24
14
44
12
How many total atoms are in the chemical formula 2H2O2?
4
6
8
12
How many total atoms are in the chemical formula 3NaCl?
6
12
3
9
What kind of system does not allow matter to enter from or escape to its surroundings?
Open system
Thermodynamic system
Closed system
None of the these
Select the best label for the image.
Compound
Element
Mixture
Atom
Put the following in the best order from the first step to the last:
Write the equation
List the elements in the same order on both sides of the equation
Count the number of atoms of each element on each side
Use coefficients to balance the equation
Check the answer.
What is the chemical symbol for helium?
(a)
What is the chemical symbol for hydrogen?
(a)
What is the chemical symbol for fluorine?
(a)
What is the chemical symbol for oxygen?
(a)
What is the chemical symbol for nitrogen?
(a)
What is the chemical symbol for sodium?
(a)
What is the chemical symbol for chlorine?
(a)
Identify the items as either elements or compounds.
Boron (B)
Calcium Carbonate (CaCO3)
Sulfuric Acid (H2SO4)
