In order to grasp the concept of molar mass calculations it is important to understand the molar unit. The mole also called mol is the basic unit of measurement in chemistry. By definition, in modern chemistry, one mole represents the number of carbon atoms in exactly 12 grams of carbon 12 isotope.
Fetal development during the first trimester. The most dramatic changes and development for your baby occur during the first trimester. Itâs also during this time that the fetus is the most susceptible to damage from alcohol, drugs, certain medications, and illnesses.
Work-place chemicals that are fat soluble such as pesticides, cleaning agents and some adhesives are capable of crossing the placenta and can be harmful to the pregnant woman. They are better avoided. Exposure to large doses of x-ray radiation can cause harmful effect to the baby during the first trimester. X-rays are generally not encouraged in the first trimester but the doses of x-ray radiation emitted by modern machines are quite small and may not have any significant ill-effect.