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.
Platinum is the more expensive metal because of it's scarcity. Platinum makes up 0.005 parts per million of the earth's crust, and the majority of platinum mined is used as an â¦ industrial catalyst such as the catalytic converters in cars.Titanium is the 9th most abundant element in the earth's crust.latinum is the more expensive metal because of it's scarcity. Platinum makes up 0.005 parts per million of the earth's crust, and the majority of platinum mined is used as an â¦ industrial catalyst such as the catalytic converters in cars.