When a solid turns into a liquid it is called fusion, more commonly referred to as melting. When a material moves from one state of matter into another it is called a phase transition. Fusion is just...
Human pregnancy can be divided roughly into three trimesters, each approximately three months long. The first trimester is from the last period to the 13th week, the second trimester is from the 14th to 27th week, and the third trimester is from the 28th week to the 42nd week. In humans, birth normally occurs at a gestational age of about 40 weeks, though it is common for births to occur from 37 to 42 weeks.
Answer: Each pregnancy is divided into three trimesters. Each trimester is roughly a third of your pregnancy. These three trimesters have different emotional and physical happenings that make them unique. Here is a guided tour through each trimester: 1  The First Trimester (Weeks 1-13) The first trimester is typically the shortest for you, because the first 3-4 weeks or more of your pregnancy, you do not even know you are pregnant. In fact, weeks 1-2 are the week of your last normal menstrual period, and when you ovulate.