Unit-3 (Revision)

Which statement about the atoms of all the isotopes of carbon is correct?

• They are all radioactive.

• They have the same mass.

• They have the same number of neutrons.

• They have the same number of electrons in the outer shell.

The table gives some properties of Group IV elements.

Which one describes the properties of silicon?

• Density=2.3 (g/cm³)

  Boiling Point=3 265 ^oC

• Density=3.1 (g/cm³)

  Boiling Point=1 997 ^oC

• Density=6.2 (g/cm³)

  Boiling Point=2 920 ^oC

• Density=24.6 (g/cm³)

  Boiling Point=11682 ^oC

Which statement about the Periodic Table is correct?

• Most metallic elements are on the left.

• Elements in the same period have the same number of outer electrons.

• Elements on the left are usually gases.

• Elements in the same group have the same number of shell.

The diagram shows elements W, X, Y and Z in a section of the Periodic Table.

Which statement about the reactivity of the elements is correct?

• X is more reactive than Y, and W is more reactive than Z.

• X is more reactive than Y, and Z is more reactive than W.

• Y is more reactive than X, and W is more reactive than Z.

• Y is more reactive than X, and Z is more reactive than W.

Which row describes isotopes of the same element?

• Row A

• Row B

• Row C

• Row D

Which row describes the structure of the sodium ion, Na⁺?

• Row A

• Row B

• Row C

• Row D

The Periodic Table lists all the known elements.

Elements are arranged in order of .......1....... number.

The melting points of Group 1 elements .......2....... down the group.

The melting points of Group 17 elements .......3....... down the group.

Which words correctly complete gaps 1, 2 and 3?

• 1: nucleon

  2: decrease

  3: increase

• 1: nucleon

  2: increase

  3: decrease

• 1: proton

  2: decrease

  3: increase

• 1: proton

  2: increase

  3: decrease

Which statements about Group 1 and Group 17 elements are correct?

Statement-1: In Group I, lithium is more reactive than potassium.

Statement-2: In Group VII, chlorine is more reactive than fluorine.

• Statement-1: True

  Statement-2: True

• Statement-1: True

  Statement-2: False

• Statement-1: False

  Statement-2: True

• Statement-1: False

  Statement-2: False

Which two properties are physical properties of all pure metals?

• brittle - poor conductor of heat

• good conductor of electricity - malleable

• poor conductor of electricity - malleable

• brittle - good conductor of heat

Which statement explains why isotopes of an element have the same chemical properties?

• They have different numbers of neutrons.

• They have the same number of electrons as protons.

• They have the same number of electrons in the outer shell.

• They have the same number of protons in the nucleus.