What is the meaning of isotopes?

• Atoms of the same element with the same nucleon number

• Atoms of the same elements with different number of neutrons

• Atoms of different elements with different proton numbers

• Atoms of different elements with the same nucleon number

The proton number of atom R is 14 and its relative atomic mass is 28. Which statement is correct?

• Mass of 1 atom of R is 28 g

• Molar mass of R is 28g mol^-1

• 14 g of R contains 6.0 X 10²³ atoms

• Atom R has 14 protons, 14 electrons and 28 neutrons

What are the reactants in this equation?

Cu(OH)₂ + 2HNO₃ → Cu(NO₃)_{2 +} 2H₂O

• Copper(II) nitrate and water

• Copper(II) nitrate and nitric acid

• Copper(II) hydroxide and nitric acid

• Copper(II) hydroxide and copper(II) nitrate

Element M and element L are located in Group 1 and Group 17 respectively. Element M react with element L to form a compund.

• ML

• ML₂

• M₂L

• M₂L₃

Element J and element Q have proton number of 12 and 9 respectively.

What is the relative formula mass(RAM) of a compound formed between J and Q?

(RAM: J=24; Q=19)

• 30

• 43

• 62

• 17

An oxide of element X has the empirical formula of X₂O. 2.24 g of element X reacts completely with 0.96 g of oxygen. What is the relative atomic mass(RAM) of X?

(RAM: O=16)

• 112

• 56

• 25

• 17

Equation: 2H₂O₂ →> 2H₂o + O₂

What is the volume of O₂ produced from the decomposition of 500cm³ of 2 mol dm^-3 hydrogen peroxide at standard temperature and pressure(STP)?

(Molar volume of gas at STP = 22.4 dm^-3 mol^-1 )

• 11.2 dm³

• 22.4 dm³

• 33.6 dm³

• 44.8 dm³

Metal X has the following properties.

-Less reactive than iron

-Does not react with iron(II) oxide

Which metal oxide can react with X?

• Zinc oxide

• Magnesium oxide

• Copper(II) oxide

• Aluminium oxide

Which statement explains why the reactivity of Group 1 elements when going down the group?

• The physical state of the elements changes from gas to liquid then to solid at room temperature

• The attractive force between valence electron and the nucleus becomes stronger

• The valence electron gets further away from the nucleus

• The melting points of the elements decrease

Some transition elements and their compounds are useful catalysts in industry. Which pair is correct?

• Iron (Manufacture of nitric acid from ammonia)

• Nickel (Manufacture of ammonia)

• Manganese(IV) oxide (Manufacture of margarine)

• Vanadium(V) oxide (Manufacture of sulphuric acid)