Compounds Vs Elements
Which of these is an atom?
A. H₂O
B. NaCl
C. O
D. CO₂
C. O
H2 + O2 → 2HO
Is this equation balanced AND HOW DO YOU KNOW?
Yes, the number of atoms is equal on both sides.
Is the chemical equation below balanced?
2H2 + O2 → H2O
Yes or No?
If no, what needs to be added or taken away to balance it?
No
a 2 (coefficient) in front of the H2O
This word means the substances you start with in a chemical reaction.
Reactants
How many atoms are in H₂?
2
Which of the following is a compound?
A. N₂
B. Fe
C. H₂O
D. O₃
C. H₂O
C + O2 → CO2
Is this equation balanced?
Yes
Is the chemical equation below balanced?
C + O2 → CO2
Yes or no?
If no, what needs to be added or taken away to balance it?
Yes
This word means the substances formed after a chemical reaction takes place.
Products
Identify and Count the atoms H₂O.
2 H (Hydrogen)
1 O (Oxygen)
A student looks at the formula CO₂. Why is it a compound?
A. It contains only one kind of atom.
B. It has more than one type of atom chemically bonded.
C. It can be broken down by physical means.
D. It has the same number of protons and electrons.
B. It has more than one type of atom chemically bonded.
N2 + 3H2 --> NH3
Is this equation balanced AND HOW DO YOU KNOW?
B. No, the reactant side has more atoms.
Is the chemical equation below balanced?
Na + Cl2 → 2NaCl
Yes or no?
If no, what needs to be added or taken away to balance it?
No
add a 2 (coefficient in front of the Na on the reactant/left side)
The arrow in a chemical equation stands for this word, meaning “produces” or “makes.”
Yield
(Total AND individual)
How many atoms are in 3CO₂?
9 total (3 Carbon & 6 Oxygen)
Which example is a single element AND a molecule?
A. H₂
B. NaCl
C. CO
D. H₂O
A. H₂
2Ag + Na2S --> Ag2S + NaI
Is this reaction balanced AND HOW DO YOU KNOW?
C. No, the reactant side has more atoms.
Is the chemical equation below balanced?
Al + O2 → Al2O3
Yes or no?
If no, what needs to be added or taken away to balance it?
No
Add a 4 to Al, a 3 to O2, & a 2 to Al2O3
A model that shows reactants turning into products with symbols and formulas is called this.
Chemical Equation
(Total AND individual)
How many atoms are in CaCl₂?
3 total (1 Calcium & 2 Chlorine)
A student compares Fe and H₂O. Which statement is correct?
A. Fe is a compound, and H₂O is an element.
B. Both are compounds because they have more than one atom.
C. Fe is an element, and H₂O is a compound.
D. Both are elements because they are made of atoms.
C. Fe is an element, and H₂O is a compound.
2Mg + O2 → 2MgO
Is this equation balanced AND HOW DO YOU KNOW?
A. Yes, the number of atoms is equal on both sides.
Is the chemical equation below balanced?
NH3 + HCl → NH4Cl
Yes or no?
If no, what needs to be added or taken away to balance it?
Yes
This law says that matter cannot be created or destroyed during a chemical reaction.
Law of Conservation of Mass
(Total AND individual)
How many atoms are in Al₂(SO₄)₃
17 total (2 Aluminum, 3 Sulfur, & 12 Oxygen)