Qualifying Child. To be considered a qualifying child, your grandchild must be under the age of 19 on the last day of the tax year, or if he's a full-time student, under the age of 24.No age restrictions apply, however, if your grandchild is permanently and totally disabled.ualifying Child. To be considered a qualifying child, your grandchild must be under the age of 19 on the last day of the tax year, or if he's a full-time student, under the age of 24.
Platinum-iridium alloy. Platinum-iridium alloys are alloys of the platinum group precious metals platinum and iridium. Typical alloy proportions are 90:10 or 70:30 (Pt:Ir). These have the chemical stability of platinum, but increased hardness. The Vickers hardness of pure platinum is 56 HV while platinum with 50% of iridium can reach over 500 HV.
In its pure form, the element is very hard to machine and very brittle. The main application of iridium is as a hardening agent of platinum. High temperature equipment such as crucibles is made from platinum-iridium alloys.Alloys made of osmium and iridium are used to produce elements of fountain pens.Given that this element is corrosive-resistant, an alloy of 10 percent iridium and 90 percent platinum was used to create the standard meter bar.n its pure form, the element is very hard to machine and very brittle. The main application of iridium is as a hardening agent of platinum. High temperature equipment such as crucibles is made from platinum-iridium alloys.