FBISE, NCP & NBF-aligned resources for Classes 9–12
Browse by Class
Browse by Type
Chemistry Chapter 4 : Topic 11
Group I Reactivity
1 / 25
A student is given three elements: Lithium (Li), Sodium (Na), and Potassium (K). He is told that all belong to Group I of the periodic table. Which statement correctly predicts their reactivity with water?
Reasoning: Reactivity increases down Group I because atomic size increases and ionization energy decreases, making it easier to lose electrons.
2 / 25
Which reason best explains why reactivity of alkali metals increases down the group?
Reasoning: Increased shielding reduces nuclear attraction on valence electron, so it is lost more easily.
3 / 25
A teacher demonstrates reactions of Group I metals with water:
Reasoning: Lithium is least reactive; potassium is more reactive and reacts violently with water.
4 / 25
Which order correctly represents increasing reactivity in Group I?
Reasoning: Reactivity increases down the group: Li → Na → K
5 / 25
A metal is stored under oil and reacts very violently with water. It is most likely:
Reasoning: Potassium is highly reactive and stored under oil to prevent reaction with air / moisture.
6 / 25
Which property decreases down Group I?
Reasoning: Atomic size increases down the group, not decreases.
7 / 25
A student observes that an unknown Group I metal reacts more violently than sodium but less than potassium. The metal is:
Reasoning: Rubidium lies between potassium and cesium in reactivity trend.
8 / 25
Which statement best explains why Group I metals are good reducing agents?
Reasoning: They have one valence electron which they easily lose.
9 / 25
When going from lithium to cesium, ionization energy:
Reasoning: Outer electron is farther from nucleus and less strongly held.
10 / 25
A metal reacts slowly with cold water but faster with hot water. It is likely:
Reasoning: Lithium is least reactive among alkali metals.
11 / 25
Which trend is correct for Group I elements?
Reasoning: Increased shielding increases reactivity.
12 / 25
A scientist predicts an unknown element below potassium in Group I. Which property is expected?
Reasoning: Reactivity increases down Group I.
13 / 25
Why do alkali metals not exist freely in nature?
Reasoning: They react quickly with air and water.
14 / 25
Which observation confirms that potassium is more reactive than sodium?
Reasoning: Greater reactivity causes faster hydrogen evolution.
15 / 25
Which factor mainly determines reactivity of Group I elements?
Reasoning: Reactivity depends on ionization energy of outer electron.
16 / 25
Which element has the largest atomic size?
Reasoning: Atomic size increases down Group I.
17 / 25
A Group I element X reacts extremely violently with water and produces an explosion. X is most likely:
Reasoning: Rubidium and cesium are extremely reactive.
18 / 25
Why does lithium react least vigorously with water?
Reasoning: Small size means strong nuclear attraction.
19 / 25
Which statement is correct about Group I metals?
Reasoning: They form + 1 ions by losing valence electron.
20 / 25
A metal is placed in water and immediately catches fire. Which property explains this?
Reasoning: Low ionization energy leads to rapid electron loss and heat release.
21 / 25
Which element would displace sodium from its compound?
Reasoning: More reactive metals displace less reactive ones.
22 / 25
Which statement is true about Group I metals?
Reasoning: Alkali metals are soft and easily cut.
23 / 25
If ionization energy decreases, reactivity of Group I metals:
Reasoning: Easier electron loss increases reactivity.
24 / 25
Which of the following correctly arranges metals by reactivity?
25 / 25
A student concludes: “The more easily an atom loses its outer electron, the more reactive it is.” This statement applies best to:
Reasoning: Alkali metals react by losing one electron.
Your score is
Restart quiz
