Atomic Structure AS

Use of the Data Booklet is relevant to this question. Which diagram correctly shows the atomic radii of the elements Mg, Al, Si and P plotted against their melting points?

• A

• B

• C

• D

Use of the Data Booklet is relevant to this question. The isotope ⁹⁹Tc is radioactive and has been found in lobsters and seaweed adjacent to nuclear fuel reprocessing plants. Which statements are correct about an atom of ⁹⁹Tc?

1 It has 13 more neutrons than protons.

2 It has 43 protons.

3 It has 99 nucleons.

• A

• B

• C

• D

The relative molecular mass, Mr, of a particular sample of chlorine is 72.0. Which properties of the atoms in this sample will be the same for all of the atoms?

1 radius

2 nucleon number

3 isotopic mass

• A

• B

• C

• D

Which ion has both more electrons than protons and more protons than neutrons?

• D^–

• H₃O⁺

• OD^–

• OH^–

Which species contains the smallest number of electrons?

Use of the Data Booklet may be appropriate for some questions.

• B³⁺

• Be²⁺

• H^–

• He⁺

What is isotope J?

• ²³⁸Np

• ²³⁸Pu

• ²⁴⁰Np

• ²⁴⁰Pu

Why is the ionic radius of a chloride ion larger than the ionic radius of a sodium ion?

• A chloride ion has one more occupied electron shell than a sodium ion.

• Chlorine has a higher proton number than sodium.

• Ionic radius increases regularly across the third period.

• Sodium is a metal, chlorine is a non-metal.

X is a particle with 18 electrons and 20 neutrons. What could be the symbol of X?

For each of the questions in this section, one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements that you consider to be correct). The responses A to D should be selected on the basis of

A -1,2,3 correct

B - 1,2 correct

C - 2,3 correct

D - 1 correct

• A

• B

• C

• D

Which isolated gaseous atom has a total of five electrons occupying spherically shaped orbitals?

• boron

• fluorine

• sodium

• potassium

Four electronic configurations are shown below. Three of these configurations belong to atoms of the elements chlorine, sodium and vanadium. Which electronic configuration belongs to an atom of another element?

• 1s² 2s² 2p⁶ 3s¹

• 1s² 2s² 2p⁶ 3s² 3p⁵

• 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³ 4s²

• 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²