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.
Pregnancy can be divided into weeks and sometimes days. A pregnancy that is â36 and 3/7 weeksâ means â36 weeks and 3 days of pregnancy.â The 40 weeks of pregnancy often are grouped into three trimesters. Each trimester lasts about 12â13 weeks (or about 3 months): First trimester: 0 weeksâ13 and 6/7 weeks (Months 1â3)