[Maximum number: 1]

What is the total number of protons and electrons in one mole of hydrogen gas?

A

2

B

4

C

$1.2 \times 10^{24}$

D

$2.4 \times 10^{24}$

[Maximum number: 1]

There are many oxides of silver with the formula $\mathrm{Ag}_{\mathrm{x}} \mathrm{O}_{\mathrm{y}}$ . All of them decompose into their elements when heated strongly.

(a)

Naturally occurring silver is composed of two stable isotopes, ${ }^{107} \mathrm{Ag}$ and ${ }^{109} \mathrm{Ag}$ .

The relative atomic mass of silver is 107.87 . Show that isotope ${ }^{107} \mathrm{Ag}$ is more abundant.

[ 1 ]

[Maximum number: 1]

There are many oxides of silver with the formula $\mathrm{Ag}_{x} \mathrm{O}_{y^{.}}$ All of them decompose into their elements when heated strongly.

(a)

Naturally occurring silver is composed of two stable isotopes, ${ }^{107} \mathrm{Ag}$ and ${ }^{109} \mathrm{Ag}$ .

The relative atomic mass of silver is 107.87 . Show that isotope ${ }^{107} \mathrm{Ag}$ is more abundant.

[ 1 ]

[Maximum number: 3]

Chlorine undergoes many reactions.

(a)

(i)

The mass spectrum of chlorine is shown.

Outline the reason for the two peaks at m / z=35 and 37 .

[ 1 ]

(ii)

Explain the presence and relative abundance of the peak at m / z=74.

[ 2 ]

[Maximum number: 3]

Chlorine undergoes many reactions.

(a)

(i)

The mass spectrum of chlorine is shown.

Outline the reason for the two peaks at m / z=35 and 37 .

[ 1 ]

(ii)

Explain the presence and relative abundance of the peak at m / z=74.

[ 2 ]

[Maximum number: 4]

When heated in air, magnesium ribbon reacts with oxygen to form magnesium oxide.

(a)

Most nitride ions are ${ }^{14} \mathrm{~N}^{3-}$ .

[ 2 ]

(i)

State the number of subatomic particles in this ion.

Protons:
Neutrons:
Electrons:

[ 1 ]

(ii)

Some nitride ions are ${ }^{15} \mathrm{~N}^{3-}$ . State the term that describes the relationship between ${ }^{14} \mathrm{~N}^{3-}$ and ${ }^{15} \mathrm{~N}^{3-}$ .

[ 1 ]

(b)

Suggest two reasons why atoms are no longer regarded as the indivisible units of matter.

[ 2 ]

[Maximum number: 1]

One definition of atomic volume is given by the formula:

\text { Atomic volume }=\frac{\text { atomic mass }\left(\mathrm{g} \mathrm{~mol}^{-1}\right)}{\text { density }\left(\mathrm{g} \mathrm{~cm}^{-3}\right)}

The table gives the atomic volumes of the first nineteen elements, in the form in which they occur at STP.

Key:

(a)

Suggest, giving one reason, whether you could ever know the actual volume of a single atom.

[ 1 ]

[Maximum number: 1]

The diagram below shows the behaviour of protons, neutrons and electrons in an electric field.

What is the correct identity of each particle?

Protons

Electrons

Neutrons

y

Z

X

x

y

z

Z

X

y

x

Z

y

[Maximum number: 1]

What is the number of subatomic particles in ${ }^{137} \mathrm{Ba}^{2+}$ ?

Protons

Neutrons

Electrons

58

81

54

56

81

54

56

137

58

137

58

[Maximum number: 1]

Which property is the same for water containing tritium $\left({ }^{3} \mathrm{H}\right)$ and water containing hydrogen $\left({ }^{1} \mathrm{H}\right)$ ?

A

Density

B

Dipole moment of a molecule

C

Boiling point

D

Relative molecular mass