ใบงาน เคมีสำหรับข้อสอบเข้าพยาบาล พร้อมเฉลย

What kind of carbon–carbon bonds do alkanes contain?

1. AAt least one double bond
2. BIonic bonds
3. COnly single bonds
4. DAt least one triple bond

อะตอมหนึ่งมีโปรตอน 6 ตัว นิวตรอน 6 ตัว และอิเล็กตรอน 6 ตัว เลขมวลของอะตอมนี้คือเท่าใด

1. A18
2. B6
3. C12
4. D0

Which of these is a polyatomic ion?

1. ASodium, Na⁺
2. BChloride, Cl⁻
3. COxide, O²⁻
4. DSulfate, SO₄²⁻

Which list is in order from smallest to largest mass?

1. AMilligram, kilogram, gram
2. BMilligram, gram, kilogram
3. CKilogram, gram, milligram
4. DGram, milligram, kilogram

Potassium forms K⁺ ions and sulfur forms S²⁻ ions. What is the name and formula of their compound?

1. APotassium sulfite, KS
2. BPotassium sulfate, K₂SO₄
3. CPotassium sulfide, KS₂
4. DPotassium sulfide, K₂S

Nitric acid (HNO₃) reacts with potassium hydroxide (KOH). Which salt forms?

1. APotassium hydride, KH
2. BPotassium nitrite, KNO₂
3. CPotassium nitrate, KNO₃
4. DNitrogen hydroxide, NOH

Why are the radioactive tracers used for medical imaging usually chosen to have short half-lives?

1. AThey give a strong signal for imaging but leave the body's tissues exposed only briefly
2. BShort half-life isotopes are not radioactive
3. CThey stay active for many years, so a single dose can be used for every future scan
4. DThey emit only alpha particles, which are harmless inside the body

Raising the temperature by 10 °C can roughly double the rate of many reactions. What is the main reason?

1. AMany more collisions have at least the activation energy
2. BThe activation energy itself is lowered by the extra heat
3. CThe particles become larger and easier to hit
4. DThe reaction becomes more exothermic