W3 April S2 Atoms and Molecules 1

The following table shows information about elements X and Y.

What is the correct number of neutrons for each element?

• X: 67

  Y: 35

• X: 165

  Y: 80

• X: 98

  Y: 45

• X: 232

  Y: 115

Element A has 7 protons. Element B has 8 more protons than A. 

If both elements are found within the first 3 periods of the Periodic Table, which statement about element B is not correct?

• B has more electron shells than A.

• B has the same number of valence electrons as A.

• B and A are found in the same group of the Periodic Table.

• B and A are found in the same period of the Periodic Table.

The nucleon number and proton number of an atom of U and an atom of V are shown below.

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

• An atom of U has fewer electrons than an atom of V.

• An atom of U has fewer neutrons than an atom of V.

• V is above U in the same group of the Periodic Table.

• U and V are in the same period of the Periodic Table.

Deuterium is an isotope of hydrogen. Which statement explains why water made from deuterium (D₂O) is called ‘heavy’ water?

• It has extra electrons.

• It has extra neutrons.

• It has extra protons.

• all of the above

Complete this table about the particles found in one atom of both isotopes.

Cl-35 neutrons =

Complete this table about the particles found in one atom of both isotopes.

Cl-35 protons =

Complete this table about the particles found in one atom of both isotopes.

Cl-37 electrons =

Complete this table about the particles found in one atom of both isotopes.

Cl-37 protons =