Your full name.

Why are the elements sodium, Na, magnesium, Mg, aluminium, Al, silicon, Si, phosphorus, P,sulphur, S, chlorine, Cl and argon, Ar in the same period?

• These elements have three valence electrons

• These elements have three physical properties

• These elements have three electron shells

• These elements have three electron

Which element forms an amphoteric oxide?

• Aluminium, Al

• Sodium, Na

• Carbon, C

• Neon, Ne

Acidic oxides will also react with alkali to form ________ and ___________

• salt

• metal oxide

• water

• acidic solution

Which oxide of an element dissolves in water to form acidic solution

• Sodium

• Magnesium

• Silicon

• Phosphorus

Across the period 3 , atomic radii of elements decrease due to 。。。(2 answers)

• proton number increase

• screening effect increase

• nucleus attraction increase

• the number of shell filled with electron increase

Which oxide of element in Period 3 does not react with water? (2 answers)

• Aluminium

• Silicon

• Phosporus

• Sulphur

Which oxide of Period 3 elements shows both acidic and basic properties?

• MgO

• Al₂O₃

• SiO₂

• ClO₂

Which oxide form acidic solution but does not dissolve in water?

• Al₂O₃

• SiO₂

• P₄O₆

• ClO₂

Name the element which exist as monoatomic gas in period 3

• Oxygen

• Chlorine

• Nitrogen

• Argon