The combination of chemical reactions through which an organism builds up or breaks down materials is called metabolism. I believe.
The answers are solution, colloid, and suspension respectively.
NaCl or salt is dissolved in the blood. So this makes blood and salts a solution. You won't be able to discern the NaCl in a solution of blood and NaCl.
Proteins in the plasma make blood a colloid. Protein particles are bigger than particles in a solution but are smaller than particles in a suspension.
Lastly, blood cells and blood make up a suspension. You would notice this characteristic in blood because red blood cells settle.
You can observe this when your blood is drawn. When it is placed in a test tube and left alone or placed in a centrifuge. The components separate into liquid on top, where you cannot see particles like salt; plasma in the middle, which has pale yellow color and also contains proteins; and the red blood cells at the bottom that settled.
Half-life = time in which half of material is lost
1/4 = 1/2 x 1/2 so 2 half lives have gone by if only 1/4 of it is left.
age of rock = 2 x half life = 2x1.3 = 2.6 billion years.