This question has 2 part(s).

This question has 2 part(s). - চর্চা

1.2 Atomic Structure & The Periodic Table

1. This question has 2 part(s).

June 2019 1F 9

1WRITTEN (3 pts)

1.1. Higher Tier Only

The following table shows some information about Group 1 elements.

Metal	Melting point (°C)	Boiling point (°C)	Density (g/cm³)	Reaction with chlorine
lithium	180	1342	0.54	reacts slowly to make a white salt
sodium	97	883	0.97	burns vigorously with a yellow flame to make a white salt
potassium	63	759	0.88	reacts violently to make a white salt
rubidium	39	688	1.53	explosive reaction
caesium	28	671	1.93	explosive reaction

i) Describe the trend in density going down the group.

[1]

ii) Explain the difference in reactivity down the group in terms of electronic structure.

[2]

সংক্ষিপ্ত উত্তর প্রশ্ন

2WRITTEN (4 pts)

1.2. The apparatus below can be used to demonstrate the reaction between sodium and chlorine.

i) Apart from the use of safety goggles, state one safety precaution that needs to be followed when using each of these elements.

[2]

ii) Complete and balance the symbol equation for the reaction that takes place between sodium and chlorine.

[2]

$□$ Na + Cl₂ $\overset{}{\rightarrow}$ $□$ ………....