Question

10. Among the following, the element with greater value of screening effect is [ ]

a) Li b) Na c) CS d) K​

Answer 1

Answer:

The more screening effect, the more electropositive (easier to lose electron when heat is provided)

Explanation:

The screening effect for elements in group 1 and 2 respectively increases from up to down

Answer 2

Answer:

The correct option is (c) Cs.

Explanation:

• When inner electrons of an atom shield the outermost electrons from the nuclear force and reduce the nuclear hold on them.
• The higher the nuclear charge, the higher the shielding effect.
• The lower the nuclear charge, the lower the shielding effect.
• Along with the group, the nuclear charge greatly increases.
• Cesium has a large nuclear charge. Its outermost electrons experience a shielding effect from the inner electrons. The outermost electrons are loosely held and can easily be given off.