ใบงาน เคมีสำหรับข้อสอบเข้าพยาบาล พร้อมเฉลย

What is the change from a gas directly to a solid, skipping the liquid state, called?

1. ADeposition
2. BCondensation
3. CFreezing
4. DSublimation

What is a single covalent bond?

1. AOne electron transferred from one atom to another
2. BTwo pairs of electrons shared between two atoms
3. COne pair of electrons shared between two atoms
4. DThe attraction between two oppositely charged ions

What does the rate of a reaction measure?

1. AHow hot the reaction gets
2. BHow quickly reactants are used up or products are formed
3. CHow much product forms in total by the end
4. DHow much energy the final products contain

เหตุใดโมเลกุลน้ำจึงมีขั้ว

1. Aโมเลกุลน้ำเป็นเส้นตรง โดยไฮโดรเจนทั้งสองอยู่ในแนวเดียวกัน
2. Bไฮโดรเจนมีอิเล็กโทรเนกาทีวิตีสูงกว่าออกซิเจน
3. Cน้ำมีพันธะไอออนิกระหว่างไฮโดรเจนกับออกซิเจน
4. Dออกซิเจนดึงอิเล็กตรอนที่ใช้ร่วมกันได้แรงกว่า และโมเลกุลมีรูปงอ

A red blood cell is placed in a concentrated (hypertonic) salt solution. What happens?

1. AWater enters the cell, which swells and may burst
2. BWater leaves the cell, which shrinks
3. CSalt leaves the cell, which swells
4. DThe cell stays the same size and shape

What is carbon-14 dating used for?

1. AFinding the exact age of rocks that are billions of years old
2. BDetecting carbon monoxide in a room
3. CEstimating the age of material that was once alive
4. DMeasuring body temperature

Each C=O bond in carbon dioxide is polar, yet the CO₂ molecule is nonpolar. Why?

1. ACarbon and oxygen have the same electronegativity
2. BThe bonds are ionic, not covalent
3. CCarbon has lone pairs that cancel the dipoles
4. DThe molecule is linear, so the two bond dipoles cancel out

Which statement correctly distinguishes a scientific law from a scientific theory?

1. AA law describes what happens; a theory explains why it happens
2. BA law is only a guess, while a theory is a proven fact
3. CLaws apply only to chemistry, theories only to biology
4. DA theory becomes a law once it is proved