Video Transcript
Which of the following period four
oxides is used as either a physical or a chemical sunscreen in many types of
commercial sunblock? (A) TiO2, (B) V2O5, (C) MnO2, (D)
CuO, or (E) Cr2O3.
In this question, we want to know
which of the period four oxides are used in sunblock. Period four metals all share the
characteristics of being strong and essential to a great number of industrial
practices. The period four d block metals
consist of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel,
copper, and zinc. The metals in the oxides given in
the answer choices include titanium, vanadium, manganese, copper, and chromium.
Titanium is a light metal, but it
has very high strength and is resistant to corrosion. One of the primary uses of titanium
is in the production of titanium–aluminum alloys. These alloys are used heavily in
the production of aircraft, armor plating, and even spacecraft. An everyday use of titanium is in
the production of titanium oxide-based sunblock.
Titanium dioxide makes an excellent
compound for sunblock, as nanoparticles of the compound can be produced, allowing
sunblock to appear invisible after it is applied to the skin. It also has a very good record for
not causing irritation to sensitive skin. Most importantly, for a sunblock,
TiO2 is very effective at blocking shortwave ultraviolet A and ultraviolet B rays
coming from the Sun.
From this information, we may
deduce that of the period four oxides given, answer choice (A) TiO2 is used in many
types of commercial sunblock.
