Elements in Period 3

Which element forms an oxide which dissolves in both nitric acid and sodium hydroxide to form a colourless solution?

• Al

• Si

• P

• S

Which property is not true regarding the elements of Period 3 when going across the period from left to right?

• The nucleon number increases

• The proton number increases

• The number of filled electron shells increases

• The number of valence electrons increases

Below shows the proton number of the elements:

L - 7

M - 8

Q - 12

R - 17

Which of the elements forms a basic oxide?

• L

• M

• Q

• R

Atom X has an electron arrangement of 2.8.7

Atom Y has 11 protons

Which of the following statements are true about elements X and Y?

(Select 3 correct answers)

• Element Y is more electropositive than element X

• Both the elements X and Y are placed in the same group of the Periodic Table

• The atomic size of element X is smaller than that of element Y

• The oxide of element X can react with sodium hydroxide solution whereas the oxide of element Y can react with nitric acid

Elements R, T and W are in the same period of the Periodic Table. The oxide of element R is amphoteric, the oxide of element T is acidic and the oxide of element W is basic. Which of the following statements are correct about elements R, T and W?

(Select 2 correct answers)

• The atomic size of the elements decreases from W, R to T

• The proton number of the elements increases from R, T to W

• The electronegatively of the elements increases from W, R to T

• The density of the elements increases from R, T to W

Below shows the proton number of the elements:

S - 11

T - 16

U - 17

V - 19

Which statement is not true?

• Atomic size increases in the order of S, T, U, V

• S and V are metals while T and U are non-metals

• S, T and U are in the same period in the Periodic Table

• Electronegativity increases in the order of V, S, T, U

Which of the following element can be found in the fireworks?

• Magnesium

• Aluminium

• Phosphorus

• Sulphur

Which of the following is an acidic oxide?

• sodium oxide

• magnesium oxide

• aluminium oxide

• sulphur dioxide

Which of the following is a metalloid?

• Sodium

• Magnesium

• Aluminium

• Silicon

Which of the following exist as a gas under room temperature?

• Sodium

• Magnesium

• Sulphur

• Chlorine