Lead is a toxic substance. the "normal" lead content in human blood is about 0.40 part per million (that is, 0.40 g of lead per million grams of blood). a value of 0.80 part per million (ppm) is considered to be dangerous. how many grams of lead are contained in 6.0 103 g of blood (the amount in an average adult) if the lead content is 0.66 ppm?

Answer : 0.0040 grams of lead is contained in the blood of an average adult human being.

Explnanation :

The lead content is given as 0.66 ppm.

That means there are 0.66 grams of lead in 1 million grams of blood.

Let us use this as a conversion factor as,

We have 6.0 x 10³ grams o blood. Te amount of lead in this is calculated as follows.

0.0040 grams of lead is contained in the blood of an average adult human being.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.