Questions on Hydrogen and Alkali Metals
Multiple-Choice Questions: Hydrogen and Alkali Metals
Hydrogen – Properties and Behavior
1. Which of the following best describes hydrogen at room temperature?
A) Solid
B) Liquid
C) Gas
D) Plasma
E) Ion
2. Hydrogen is located in Group 1 of the periodic table because:
A) It has one proton
B) It behaves like a noble gas
C) It forms one covalent bond
D) It has one valence electron
E) It is a metal
3. Which isotope of hydrogen contains one proton and one neutron?
A) Protium
B) Deuterium
C) Tritium
D) Helium
E) None of the above
4. Hydrogen gas (H₂) is:
A) Diatomic
B) Monatomic
C) Triatomic
D) Polyatomic
E) Non-molecular
5. Which of the following is a use of hydrogen?
A) Fuel cells
B) Coolant in nuclear reactors
C) Rocket fuel
D) All of the above
E) None of the above
6. Tritium is radioactive because:
A) It has no electrons
B) It has too many protons
C) It has too many neutrons
D) It is unstable due to low energy
E) It reacts with oxygen
7. Which of the following best describes the placement of hydrogen on the periodic table?
A) Metal in Group 2
B) Non-metal in Group 1
C) Noble gas in Group 18
D) Metalloid in Group 13
E) Transition element
8. Hydrogen forms what type of bond with nonmetals?
A) Ionic
B) Hydrogen
C) Metallic
D) Covalent
E) Coordinate
9. Which compound contains hydrogen bonded to a highly electronegative atom, enabling hydrogen bonding?
A) CH₄
B) NH₃
C) NaH
D) HCl
E) HF
10. Which of these is not a property of hydrogen?
A) Highly flammable
B) Lightest element
C) Metal
D) Used in stars
E) Has one proton
Alkali Metals – Group 1 Elements
11. Which of the following is not an alkali metal?
A) Lithium
B) Sodium
C) Potassium
D) Calcium
E) Cesium
12. Which alkali metal is the most reactive with water?
A) Lithium
B) Sodium
C) Potassium
D) Rubidium
E) Cesium
13. Which of the following best describes alkali metals' reactivity trend down the group?
A) Decreases
B) Increases
C) Remains constant
D) Varies irregularly
E) First increases, then decreases
14. What is the general oxidation state of alkali metals in compounds?
A) 0
B) +2
C) –1
D) +1
E) –2
15. Alkali metals are stored in oil because:
A) They are slippery
B) They corrode easily
C) They react with air and moisture
D) They dissolve in water
E) They are explosive
16. What color flame does sodium produce in a flame test?
A) Red
B) Green
C) Violet
D) Yellow
E) Blue
17. Which of these alkali metals has the lowest atomic number?
A) Potassium
B) Sodium
C) Lithium
D) Rubidium
E) Francium
18. Alkali metals have:
A) High density
B) High melting points
C) Low melting points
D) Poor conductivity
E) High electronegativity
19. What is a general property of alkali metals?
A) Hard and brittle
B) Conduct electricity
C) Inert in water
D) Not reactive with oxygen
E) Non-metallic
20. Which of the following alkali metals is radioactive?
A) Lithium
B) Francium
C) Sodium
D) Potassium
E) Rubidium
Reactions and Applications
21. When an alkali metal reacts with water, the products are:
A) Metal hydroxide + hydrogen gas
B) Metal oxide + hydrogen gas
C) Metal nitride + ammonia
D) Salt + carbon dioxide
E) Metal carbonate + oxygen
22. The group of alkali metals includes how many naturally occurring elements?
A) 5
B) 6
C) 7
D) 8
E) 4
23. What causes the reactivity trend in alkali metals down the group?
A) Decreasing ionization energy
B) Increasing atomic radius
C) Decreasing electronegativity
D) All of the above
E) None of the above
24. Potassium is important in the human body for:
A) Bone strength
B) Oxygen transport
C) Nerve function and muscle contraction
D) Immune defense
E) Hormone production
25. Which alkali metal is commonly used in medicine for mood disorders?
A) Sodium
B) Lithium
C) Potassium
D) Rubidium
E) Cesium
26. What is the formula for the compound formed by sodium and chlorine?
A) Na₂Cl
B) NaCl
C) NaCl₂
D) Na₂Cl₂
E) Na₃Cl
27. Which alkali metal is a liquid at room temperature under standard pressure?
A) Rubidium
B) Cesium
C) None
D) Potassium
E) Francium
28. Which of the following is correct about the density of alkali metals?
A) All are denser than water
B) Only lithium floats on water
C) All except lithium float
D) Lithium, sodium, and potassium float
E) None float on water
29. Which of the following is not a typical reaction of hydrogen?
A) Combustion
B) Acting as a reducing agent
C) Forming ionic bonds with halogens
D) Forming covalent bonds
E) Acting as a catalyst
30. In which type of chemical reaction is hydrogen gas commonly released?
A) Neutralization
B) Metal + acid
C) Precipitation
D) Decomposition of carbonates
E) Double displacement
Answers and Explanations
1. C – Gas
→ Hydrogen is a colorless, odorless gas at room temperature.
2. D – It has one valence electron
→ That places it in Group 1, though it’s a non-metal.
3. B – Deuterium
→ Deuterium has 1 proton and 1 neutron.
4. A – Diatomic
→ Hydrogen exists naturally as H₂ molecules.
5. D – All of the above
→ Hydrogen has multiple industrial and scientific uses.
6. C – It has too many neutrons
→ Tritium has 2 neutrons, making it unstable and radioactive.
7. B – Non-metal in Group 1
→ Unique non-metal, often placed above alkali metals.
8. D – Covalent
→ Hydrogen commonly forms covalent bonds.
9. E – HF
→ HF exhibits strong hydrogen bonding.
10. C – Metal
→ Hydrogen is a non-metal.
11. D – Calcium
→ Calcium is an alkaline earth metal.
12. E – Cesium
→ Reacts explosively with water due to low ionization energy.
13. B – Increases
→ Reactivity increases down the group due to easier electron loss.
14. D – +1
→ Alkali metals lose one electron to form +1 cations.
15. C – They react with air and moisture
→ Stored in oil to prevent explosive reactions.
16. D – Yellow
→ Sodium gives a bright yellow flame.
17. C – Lithium
→ Atomic number 3, the lightest alkali metal.
18. C – Low melting points
→ All alkali metals have relatively low melting points.
19. B – Conduct electricity
→ Like all metals, they are good conductors.
20. B – Francium
→ Extremely rare and radioactive.
21. A – Metal hydroxide + hydrogen gas
→ Alkali metals + water → hydroxide + H₂
22. B – 6
→ Lithium, Sodium, Potassium, Rubidium, Cesium, Francium.
23. D – All of the above
→ These factors make them more reactive down the group.
24. C – Nerve function and muscle contraction
→ Potassium plays a vital biological role.
25. B – Lithium
→ Used to treat bipolar disorder.
26. B – NaCl
→ Common table salt.
27. C – None
→ All are solid at room temperature under normal pressure.
28. D – Lithium, sodium, and potassium float
→ Their densities are less than water.
29. E – Acting as a catalyst
→ Hydrogen is not typically a catalyst itself.
30. B – Metal + acid
→ This reaction commonly releases hydrogen gas
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