Medicine Mission Assessment
Medicine Mission Assessment
Name:
Date:
Exploring how small changes in atoms make better medicines.
The Challenge: Improving Ibuprofen
Scientists want to make medicines safer. Ibuprofen is a common medicine for pain, but it can sometimes hurt the stomach or kidneys if taken too much.
Scientists created a new version called Sila-ibuprofen. They took the Ibuprofen molecule and replaced one Carbon (C) atom with one Silicon (Si) atom.
Ibuprofen Structure
C
Original Carbon Center
Sila-ibuprofen Structure
Si
New Silicon Center
Question 1: Why can Silicon (Si) replace Carbon (C) and still make the same number of bonds?
Hint: Look at the Group (column) on the Periodic Table. Are they in the same column?
Your Response:
Silicon can replace Carbon because they are both in Group ________ on the Periodic Table, which means they both have ________ valence electrons. This allows them to make...
Comparing the Atoms
| Atom Name | Symbol | Atomic Radius
(Size) | Protons
(Positive Charge) | Electronegativity
(Pulling Power) |
| --- | --- | --- | --- | --- |
| Hydrogen | H | 25 pm | 1 | 2.20 |
| Carbon | C | 70 pm | 6 | 2.55 |
| Silicon | Si | 114 pm | 14 | 1.90 |
Question 2: Why is Silicon (114 pm) much larger than Carbon (70 pm)?
Your Response:
Silicon is larger than Carbon because Silicon has more energy ________ (shells), while Carbon only has ________. This makes Silicon...
Question 3: Why is Silicon's pulling power (electronegativity) lower than Carbon's?
Coulomb’s Law Reminder: Attraction is stronger when the distance between the nucleus and electrons is shorter.
Your Response:
Silicon has a lower electronegativity because its radius is ________. This means the valence electrons are ________ from the nucleus. According to Coulomb's Law, this makes the force of attraction ________...
Bonding and Polarity
Rule for Polarity:
- • Difference 0.0 to 0.4 = Nonpolar (Equal sharing)
- • Difference 0.5 to 1.7 = Polar (Unequal sharing)
Question 4: Complete the bond table.
| Bond | Calculation
(Subtract values) | Bond Type
(Polar or Nonpolar?) | Rank Polarity
(1=Most, 4=Least) | Which atom
pulls more? |
| --- | --- | --- | --- | --- |
| C — C | 2.55 - 2.55 = 0 | Nonpolar | 4 | None (Equal) |
| C — H | 2.55 - 2.20 = ________ | | | |
| Si — H | 2.20 - 1.90 = ________ | | | |
| C — Si | 2.55 - 1.90 = ________ | | | |
Question 5: Draw dipole arrows (→) on the bond lines below.
Tip: The arrow points toward the atom that pulls harder (higher electronegativity).
IBUPROFEN SECTION
C
C
C
H
Draw arrows on the gray bond lines
SILA-IBUPROFEN SECTION
C
Si
C
H
Draw arrows on the gray bond lines
The Result: Why it works better
Question 6: How does changing Carbon to Silicon change the polarity and electric field?
δ−
Partial Negative
(More Electrons)
δ+
Partial Positive
(Fewer Electrons)
Your Response:
In Ibuprofen, the Carbon pulls electrons ________ from the Hydrogen. This makes the Hydrogen more ________.
In Sila-ibuprofen, the Silicon has a ________ pull, which causes the electrons to shift ________...
Scientific Fact: Solubility
Ibuprofen does not dissolve well in water. It is usually taken as a pill.
Sila-ibuprofen dissolves much better. This allows it to be given as an IV drip (liquid medicine) directly into the blood.
Ibuprofen
Pill
Sila-ibuprofen
IV Drip
Question 7: Explain why Sila-ibuprofen dissolves better in water.
Helpful Vocabulary Word Bank
Polarity Partial Charge Water Molecules Attraction Dissolve Coulomb's Law Electric Field Intermolecular Force
Your Response:
Sila-ibuprofen dissolves better because it has a higher ________. This means there is a stronger ________ between the medicine and the ________...
