Titanium is a strong yet lightweight metal that is corrosion-resistant. It is commonly used to strengthen structural materials like aircraft and missiles. Titanium dioxide is also widely used as a white pigment in paints due to its hiding power and permanence. Zirconium is used in applications where corrosion resistance is important, like chemical industries and vacuum tubes. It is also used in alloys and refractory materials. Hafnium is primarily employed in nuclear reactor control rods due to its high neutron absorption. Rutherfordium is an artificial element with no natural occurrence or applications.