Question
17. One molecule of Iodine (I2) and two molecules of sodium chloride (NaCl) combine in a reaction. How many atoms are in the products?
A) 3
B) 4
C) 2
D) 6
18. Are the following examples of chemical or physical changes?
Column A
1.
A silver spoon tarnishing:
A silver spoon tarnishing
2.
Blowing a dandelion:
Blowing a dandelion
3.
Building a sand castle:
Building a sand castle
4.
Toasting bread:
Toasting bread
Column B
A) Chemical change
B) Physical change
19. Which statement comparing ionic and covalent bonds is correct?
a
Covalent bonds tend to be less polar than ionic bonds.
b
Elements in Group 1A are more likely to form covalent bonds than ionic bonds with other atoms.
c
More electrons are transferred from covalent bonds than ionic bonds.
d
The difference between electronegativities is greater in covalent bonds than for atoms in ionic bonds.
20. Balance the following the chemical equation: _ Mg + _ F2 → _ MgF2
a
2:1:1
b
1:1:1
c
1:1:2
d
1:2:1
A) 3
B) 4
C) 2
D) 6
18. Are the following examples of chemical or physical changes?
Column A
1.
A silver spoon tarnishing:
A silver spoon tarnishing
2.
Blowing a dandelion:
Blowing a dandelion
3.
Building a sand castle:
Building a sand castle
4.
Toasting bread:
Toasting bread
Column B
A) Chemical change
B) Physical change
19. Which statement comparing ionic and covalent bonds is correct?
a
Covalent bonds tend to be less polar than ionic bonds.
b
Elements in Group 1A are more likely to form covalent bonds than ionic bonds with other atoms.
c
More electrons are transferred from covalent bonds than ionic bonds.
d
The difference between electronegativities is greater in covalent bonds than for atoms in ionic bonds.
20. Balance the following the chemical equation: _ Mg + _ F2 → _ MgF2
a
2:1:1
b
1:1:1
c
1:1:2
d
1:2:1
Answers
GPT-4o mini
Here are the answers to your questions:
**17. How many atoms are in the products when one molecule of Iodine (I2) and two molecules of sodium chloride (NaCl) combine?**
- I2 contributes 2 iodine atoms.
- 2 NaCl contributes 2 sodium atoms and 2 chlorine atoms, which totals 4 atoms (2 Na + 2 Cl).
- Therefore, the total number of atoms in the products is 2 (from I2) + 4 (from NaCl) = **6 atoms**.
- **Answer: D) 6**
---
**18. Are the following examples of chemical or physical changes?**
1. A silver spoon tarnishing:
- A) Chemical change
2. Blowing a dandelion:
- B) Physical change
3. Building a sand castle:
- B) Physical change
4. Toasting bread:
- A) Chemical change
---
**19. Which statement comparing ionic and covalent bonds is correct?**
- a) Covalent bonds tend to be less polar than ionic bonds. (True)
- b) Elements in Group 1A are more likely to form covalent bonds than ionic bonds with other atoms. (False - they typically form ionic bonds)
- c) More electrons are transferred from covalent bonds than ionic bonds. (False)
- d) The difference between electronegativities is greater in covalent bonds than for atoms in ionic bonds. (False)
Therefore, the correct statement is **a)** "Covalent bonds tend to be less polar than ionic bonds."
---
**20. Balance the following chemical equation: _ Mg + _ F2 → _ MgF2.**
- To balance the equation, you need 1 magnesium (Mg) and 2 fluorine (F) atoms for every formula unit of magnesium fluoride (MgF2). Therefore, the coefficients are:
- 1 Mg + 1 F2 → 1 MgF2
This gives a balanced equation of: **1:1:1**. **Answer: b) 1:1:1**
**17. How many atoms are in the products when one molecule of Iodine (I2) and two molecules of sodium chloride (NaCl) combine?**
- I2 contributes 2 iodine atoms.
- 2 NaCl contributes 2 sodium atoms and 2 chlorine atoms, which totals 4 atoms (2 Na + 2 Cl).
- Therefore, the total number of atoms in the products is 2 (from I2) + 4 (from NaCl) = **6 atoms**.
- **Answer: D) 6**
---
**18. Are the following examples of chemical or physical changes?**
1. A silver spoon tarnishing:
- A) Chemical change
2. Blowing a dandelion:
- B) Physical change
3. Building a sand castle:
- B) Physical change
4. Toasting bread:
- A) Chemical change
---
**19. Which statement comparing ionic and covalent bonds is correct?**
- a) Covalent bonds tend to be less polar than ionic bonds. (True)
- b) Elements in Group 1A are more likely to form covalent bonds than ionic bonds with other atoms. (False - they typically form ionic bonds)
- c) More electrons are transferred from covalent bonds than ionic bonds. (False)
- d) The difference between electronegativities is greater in covalent bonds than for atoms in ionic bonds. (False)
Therefore, the correct statement is **a)** "Covalent bonds tend to be less polar than ionic bonds."
---
**20. Balance the following chemical equation: _ Mg + _ F2 → _ MgF2.**
- To balance the equation, you need 1 magnesium (Mg) and 2 fluorine (F) atoms for every formula unit of magnesium fluoride (MgF2). Therefore, the coefficients are:
- 1 Mg + 1 F2 → 1 MgF2
This gives a balanced equation of: **1:1:1**. **Answer: b) 1:1:1**