Do you really know about us? [Group 18 and Group 1]

We are the elements in Group 18.

Can you guess who are we?

• Lithium

• Helium

• Argon

• Hydrogen

• Xenon

Group 18 also known as

Group 18 elements are chemically unreactive.

Which statements will explain about this ?

there will be more than 1 answer

• Helium atom already achieve stable octet electron arrangement

• Neon atom already achieve stable octet electron arrangement

• Neon atom already achieve stable duplet electron arrangement

• Group 18 elements have already achieve stable duplet and octet electron arrangement

• Helium atom already achieve stable duplet electron arrangement

Group 18 : "Which statements describe our physical properties as we going down the Group?"

• Density increase

• Atomic size become bigger

• melting and boiling point increase

• Reactivity increas

Group 18:As we going down the group, our melting and boiling point increases.

Can you explain why?

• Atomic size become bigger

• Van Der Waals forces between atoms become stronger

• Reactivity increase

• Less heat energy needed to overcome the forces between the atoms

My symbol is K.

Who am I?

We are the elements in Group 1.

Can you identify us?

• Helium

• Potassium

• Lithium

• Rubidium

• Caesium

Sodium and Lithium: " We are located in the same group. Can you explain why?"

• Both atoms already achieve stable octet electron arrangement

• Both atoms have 1 occupied shell with electrons

• Both atoms have 1 valence electrons

• Both atoms have 1 electron in the outermost occupied shell

• Both atoms have same physical properties

Group 1: " We can react with water. Which observations are correct to describe our reaction with water?'

[You can choose more than 1 answer]

• Produce hiss sound

• Move randomly with different speed based on the reactivity of the metals towards water

• Produce hydrogen gas and alkaline solution

• Float on water during the reaction

• The reactivity increase from Li, Na, K, Rb, Cs, Fr

Potassium is more reactive than Lithium.

Do you know why?

[Choose ALL the correct statement to describe this situation]

• Potassium atom is bigger than lithium atom

• More easy for Potassium atom to donate/ release its valence electron

• Force of attraction between nucleus and valence electron in potassium atom is more stronger than lithium atom

• Potassium atom have low melting and boiling point than Li atom

• Potassium atom more denser than Li atom