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.
FETAL DEVELOPMENT. FIRST TRIMESTER. IMPLANTATION. Development begins on the day a womanâs egg is fertilized by a sperm. penetrating it. The fertilized egg or zygote immediately begins to. divide into 2 cells, then 4, then 8, and so on. Within a few days the. cluster of between 13 and 32 cells leave the fallopian tube and move. into the uterus. This group of cells is now called a blastocyst and. has increased in size to hundreds of cells.