The d block and the first series in use
Answers are for parents and teachers.
1
Titanium has Z = 22 and silver has Z = 47. For each, say which series it is in and which element of that series it is.
Titanium: 22 − 20 = 2, the 2nd element of the 3d series. Silver: the 4d series starts at Z = 39, so 47 − 38 = 9, the 9th element of the 4d series.
2
Make a table with the columns Element, Property, Use for Mn, Ni, Zn, V and Co, one line each.
Mn: brittle alone, harder alloys: rails and drink cans. Ni: resists rust and acids: hard steels, plating, heating coils. Zn: protects iron: galvanising. V: hardens steel and resists corrosion: springs. Co: can be magnetised: magnets and rechargeable cells.
3
In two sentences, explain why a steel roof sheet may be galvanised, and why aircraft parts may be made of titanium rather than steel.
Zinc coats the steel and keeps air and water from the iron, so it does not rust. Titanium is about as strong as steel but lighter, which saves mass in an aircraft.
4
An f sublevel has 7 orbitals. How many elements are there in a row of the f block, and how do you know?
7 × 2 = 14 elements, because each orbital holds 2 electrons and each added electron gives a new element.
5
Name the three elements of the 3d series that lie in the three columns numbered 8, 9 and 10, and give two things said about them this week.
Iron, cobalt and nickel. They resemble one another along a row more than they resemble the elements below them, and all three can be magnetised.