contains (no atoms, one atom) of that element.
7. the total number of atoms in fe₂o₃ is (two, five, six).
8. there are (three, seven, ten) different elements in h₂so₄.
9. an atom is chemically stable if its outer energy level (is filled with, contains no) electr
10. for atoms of most noble gases and most other elements, the outer energy level is full w has (three, eight) electrons.
11. the noble gases do not readily form compounds because they (are, are not) chemically s
12. a chemical bond is a (force, chemical) that holds atoms together in a compound.
13. chemical bonds form when atoms lose, gain, or (share, multiply) electrons.
directions: complete the table below by using the formula of each compound to identify the element each compound contains and the number of atoms of each of these elements in a unit of the compoun formula has been done for you.

| formula | element 1 | element 2 | element 3 |
| --- | --- | --- | --- |
| h₂o | 2 hydrogen | 1 oxygen | |
| 14. naoh | | | |
| 15. nacl | | | |
| 16. nh₃ | | | |
| 17. h₂so₄ | | | |
| 18. sio₂ | | | |

Question

contains (no atoms, one atom) of that element.
7. the total number of atoms in fe₂o₃ is (two, five, six).
8. there are (three, seven, ten) different elements in h₂so₄.
9. an atom is chemically stable if its outer energy level (is filled with, contains no) electr
10. for atoms of most noble gases and most other elements, the outer energy level is full w has (three, eight) electrons.
11. the noble gases do not readily form compounds because they (are, are not) chemically s
12. a chemical bond is a (force, chemical) that holds atoms together in a compound.
13. chemical bonds form when atoms lose, gain, or (share, multiply) electrons.
directions: complete the table below by using the formula of each compound to identify the element each compound contains and the number of atoms of each of these elements in a unit of the compoun formula has been done for you.

| formula | element 1 | element 2 | element 3 |
| --- | --- | --- | --- |
| h₂o | 2 hydrogen | 1 oxygen |  |
| 14. naoh |  |  |  |
| 15. nacl |  |  |  |
| 16. nh₃ |  |  |  |
| 17. h₂so₄ |  |  |  |
| 18. sio₂ |  |  |  |

Accepted Answer

### Question 7:
# Explanation:
## Step1: Identify atoms in $\ce{Fe2O3}$
In $\ce{Fe2O3}$, the subscript of Fe is 2, so there are 2 Fe atoms. The subscript of O is 3, so there are 3 O atoms.
## Step2: Calculate total atoms
Total atoms = Number of Fe atoms + Number of O atoms = $2 + 3 = 5$.
# Answer: five

### Question 8:
# Explanation:
## Step1: Identify elements in $\ce{H2SO4}$
The formula $\ce{H2SO4}$ contains H (Hydrogen), S (Sulfur), and O (Oxygen).
## Step2: Count the number of elements
There are 3 different elements (H, S, O).
# Answer: three

### Question 9:
# Explanation:
An atom is chemically stable when its outer energy level is filled with electrons (this is based on the octet rule concept, where a full outer shell makes the atom stable). The option "contains no" would mean the outer level is empty, which is unstable.
# Brief Explanations:
An atom's outer energy level being filled with electrons makes it stable (octet rule concept). "Contains no" electrons in outer level would be unstable.
# Answer: is filled with

### Question 10:
# Explanation:
For most noble gases and other elements, the outer energy level is full with 8 electrons (octet rule: atoms tend to achieve 8 electrons in the outer shell for stability, except for some exceptions like H, He). The option "three" is incorrect as 8 is the typical stable number for outer shell (octet).
# Brief Explanations:
Octet rule states most atoms have 8 electrons in outer shell for stability (noble gases except He follow this, and other elements aim for it). So outer level has 8 electrons.
# Answer: eight

### Question 11:
# Explanation:
Noble gases have filled outer electron shells, which makes them chemically stable. Because they are stable, they do not readily form compounds (since they don't need to gain/lose/share electrons to achieve stability). So the correct option is "are" (chemically stable).
# Brief Explanations:
Noble gases have full outer electron shells, making them chemically stable. Stable atoms don't readily form compounds, so they "are" chemically stable.
# Answer: are

### Question 12:
# Explanation:
A chemical bond is a force that holds atoms together in a compound. "Chemical" is not the correct term here as a bond is a force (electrostatic or other types of forces) between atoms.
# Brief Explanations:
A chemical bond is a force (electrostatic, etc.) that holds atoms together. "Chemical" is not the right term for what holds atoms; it's a force.
# Answer: force

### Question 13:
# Explanation:
Chemical bonds form when atoms lose, gain, or share electrons. Ionic bonds involve losing/gaining electrons, covalent bonds involve sharing. "Multiply" electrons is not a process in bond formation.
# Brief Explanations:
Ionic bonds: lose/gain electrons; covalent bonds: share electrons. "Multiply" is not a bond - forming process.
# Answer: share

### Question 14: $\ce{NaOH}$
# Explanation:
## Step1: Identify elements in $\ce{NaOH}$
$\ce{NaOH}$ has Na (Sodium), O (Oxygen), and H (Hydrogen).
## Step2: Determine number of atoms for each element
- Na: subscript 1, so 1 sodium.
- O: subscript 1, so 1 oxygen.
- H: subscript 1, so 1 hydrogen.
# Answer:
Element 1: 1 sodium
Element 2: 1 oxygen
Element 3: 1 hydrogen

### Question 15: $\ce{NaCl}$
# Explanation:
## Step1: Identify elements in $\ce{NaCl}$
$\ce{NaCl}$ has Na (Sodium) and Cl (Chlorine).
## Step2: Determine number of atoms for each element
- Na: subscript 1, so 1 sodium.
- Cl: subscript 1, so 1 chlorine.
# Answer:
Element 1: 1 sodium
Element 2: 1 chlorine
(No Element 3 as it's a binary compound)

### Question 16: $\ce{NH3}$
# Explanation:
## Step1: Identify elements in $\ce{NH3}$
$\ce{NH3}$ has N (Nitrogen) and H (Hydrogen).
## Step2: Determine number of atoms for each element
- N: subscript 1, so 1 nitrogen.
- H: subscript 3, so 3 hydrogen.
# Answer:
Element 1: 1 nitrogen
Element 2: 3 hydrogen
(No Element 3 as it's a binary compound)

### Question 17: $\ce{H2SO4}$
# Explanation:
## Step1: Identify elements in $\ce{H2SO4}$
$\ce{H2SO4}$ has H (Hydrogen), S (Sulfur), and O (Oxygen).
## Step2: Determine number of atoms for each element
- H: subscript 2, so 2 hydrogen.
- S: subscript 1, so 1 sulfur.
- O: subscript 4, so 4 oxygen.
# Answer:
Element 1: 2 hydrogen
Element 2: 1 sulfur
Element 3: 4 oxygen

### Question 18: $\ce{SiO2}$
# Explanation:
## Step1: Identify elements in $\ce{SiO2}$
$\ce{SiO2}$ has Si (Silicon) and O (Oxygen).
## Step2: Determine number of atoms for each element
- Si: subscript 1, so 1 silicon.
- O: subscript 2, so 2 oxygen.
# Answer:
Element 1: 1 silicon
Element 2: 2 oxygen
(No Element 3 as it's a binary compound)

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Question 7:

Step1: Identify atoms in $\ce{Fe2O3}$

Step2: Calculate total atoms

Step1: Identify elements in $\ce{H2SO4}$

Step2: Count the number of elements

Answer:

Question 8: