Question
Magnesium is a metal.
(a) Name and describe the bonding in magnesium.
name…………………………..
description of bonding………………[4]
(b) Magnesium oxide, $\mathrm{MgO}$, is formed when magnesium burns in oxygen.
(i) Complete the dot-and-cross diagram to show the electron arrangement of the ions in magnesium oxide.
The inner shells have been drawn.
Give the charges on the ions.
(ii) Write the chemical equation for the reaction that occurs when magnesium burns in oxygen.[2]
(c) Magnesium oxide also forms when magnesium nitrate, $\mathrm{Mg}\left(\mathrm{NO}_3\right)_2$, is heated strongly. This is an endothermic reaction.
(i) Write the chemical equation for this reaction.[2]
(ii) What type of reaction is this?[1]
(iii) Name two other compounds of magnesium that form magnesium oxide when heated.[2] [Total: 14]
▶️Answer/Explanation
Ans:
2(a) metallic (bonding) 1
sea of electrons 1
positive ions 1
attraction between 1
2(b)(i) Mg octet of eight dots 1
O octet of six crosses and two dots. 1
correct charges on both ions 1
2(b)(ii) $
2 \mathrm{Mg}+\mathrm{O}_2 \rightarrow 2 \mathrm{MgO}
$
M1 species
M2 balancing
2(c)(i) $\begin{aligned} & 2 \mathrm{Mg}\left(\mathrm{NO}_3\right)_2 \rightarrow 2 \mathrm{MgO}+4 \mathrm{NO}_2+\mathrm{O}_2 \\ & \mathrm{M} 1 \text { product species } \\ & \mathrm{M} 2 \text { balancing }\end{aligned}$
2(c)(ii) (thermal) decomposition
2(c)(iii) magnesium carbonate
magnesium hydroxide
Question
An isotope of sodium is written as shown.
\(_{11}^{23}\textrm{Na}\)
(a) (i) Deduce the number of protons, electrons and neutrons in this isotope of sodium.[3]
number of protons
number of electrons
number of neutrons
(ii) State one medical use of radioactive isotopes.[1]
(b) (i) Draw the electronic structure of a sodium atom. [2]
(ii) State the name of the particle which is lost when a sodium atom forms a sodium ion.[1]
(c) Sodium reacts with water to form:
-
- an alkaline solution
- a gas which ‘pops’ with a lighted splint.
(i) Complete the word equation for the reaction of sodium with water.
(ii) The reaction of sodium with water is exothermic.
What is meant by the term exothermic?[1]
(iii) Sodium reacts with oxygen to form sodium oxide.
Is sodium oxide an acidic oxide or a basic oxide?
Give a reason for your answer.[1]
(d) The table shows some observations for the reaction of four metals with cold water and with hot water.
Use this information to put the four metals in order of their reactivity.
Put the least reactive metal first.
[2] [Total: 13]
Answer/Explanation
Ans:
(a)(i) protons: 11 (1)
electrons: 11 (1)
neutrons: 12 (1)
(a)(ii) treating cancer / thyroid function / tracer for diagnosis
(b)(i) electron in outer shell (1)
electrons in first shell AND eight electrons in the second shell (1)
(b)(ii) electron
(c)(i) sodium hydroxide (1)
hydrogen (1)
(c)(ii) heat given out / heat evolved
(c)(iii) basic (no mark alone)
AND
sodium is a metal (1)
(d) manganese < uranium < lanthanum < calcium (2)
if 2 marks not scored allow 1 mark for 1 consecutive pair reversed
Question
Flerovium, Fl, atomic number 114, was first made in research laboratories in 1998.
(a) Flerovium was made by bombarding atoms of plutonium, Pu, atomic number 94, with atoms of element Z.
-
- The nucleus of one atom of plutonium combined with the nucleus of one atom of element Z.
- This formed the nucleus of one atom of flerovium.
Suggest the identity of element Z.[1]
(b) In which period of the Periodic Table is flerovium?[1]
(c) Predict the number of outer shell electrons in an atom of flerovium.[1]
(d) Two isotopes of flerovium are 286Fl and 289Fl. The nuclei of both of these isotopes are unstable and emit energy when they split up.
(i) State the term used to describe isotopes with unstable nuclei.[1]
(ii) Complete the table to show the number of protons, neutrons and electrons in the atoms of the isotopes shown.[2]
(e) Only a relatively small number of atoms of flerovium have been made in the laboratory and the properties of flerovium have not yet been investigated.
It has been suggested that flerovium is a typical metal.
(i) Suggest two physical properties of flerovium.[2]
1
2
(ii) Suggest one chemical property of flerovium oxide.[1] [Total: 9]
Answer/Explanation
Ans:
(a) calcium / Ca
(b) 7
(c) 4
(d)(i) radioisotopes
(d)(ii) 286Fl 114p 172n 114e
289Fl 114p 175n 114e
(e)(i) any two from:
high melting point / boiling point
hard
dense
conduct electricity
conduct heat
ductile / malleable
sonorous
lustrous / shiny
(e)(ii) basic (oxide)