Transition elements
6 Use the information given in the table below to answer the questions below concerning the elements Q, R, S, T and X. Element
Proton number
Nucleon number
Q
3
7
R
20
S
Electronic structure
7 a Consider the chemical properties and physical properties of the halogens chlorine, bromine and iodine. Using these properties, predict the following about the other two halogens, fluorine and astatine.
2,1
Property
40
2,8,8,2
18
40
2,8,8
State at room temperature and pressure
T
8
18
2,6
Colour
X
19
39
2,8,8,1
Reactivity with sodium metal
a Which element has 22 neutrons in each atom? b Which element is a noble gas? c Which two elements form ions with the same electronic structure as neon? d Which two elements are in the same group of the Periodic Table and which group is this? e Place the elements in the table into the periods in which they belong. f Which is the most reactive metal element shown in the table? g Which of the elements is calcium?
Fluorine
b (i) Write a word equation for the reaction of fluorine gas with sodium chloride solution. (ii) Write a balanced chemical equation for the reaction, with state symbols. (iii) Write an ionic equation for the reaction, with state symbols. 8 Some of the most important metals we use are found in the transition element section of the Periodic Table. One of these elements is copper. Sodium, a Group I metal, has very different properties from those of copper. Complete the table below to show their differences. Transition element, e.g. copper Hardness (hard/soft) Reactivity Density (high/low) Catalytic activity Variable oxidation states
148
Astatine
Group I metal, e.g. sodium