These elements, unlike the transition elements, do not exhibit variable oxidation states, and their valence electrons are only present in their outer shell. All of these elements are solid, have a relatively high density, and are opaque. They have oxidation numbers of +3, Â±4, and -3. The Other Metals are: Aluminum Gallium Indium Tin Thallium Lead Bismuth This website is copyright Â© 1996-2012 Yinon Bentor. The 7 elements classified as other metals are located in groups 13, 14, and 15.
1 The embryo grows rapidly, and the baby's external features begin to form. 2  Your baby's brain, spinal cord, and heart begin to develop. 3  Baby's gastrointestinal tract starts to form.  It is during this time in the first trimester that the baby is most at risk for damage from things that may cause birth defects.
During the first eight weeks, a fetus is called an embryo. The embryo develops rapidly and by the end of the first trimester, it becomes a fetus that is fully formed, weighing approximately 0.5 to 1 ounce and measuring, on average, 3 to 4 inches in length.