A zygote is the initial cell formed after a sperm and egg have joined. A blastocyst begins at day 5 in mammals after fertilization. This all occurs during the first week of being conceived. After the first week, the developing life form becomes an embryo, and the embryo is the stage where DNA is built..After week 9 in a human lifeform, it is considered a fetus. zygote is the initial cell formed after a sperm and egg have joined. A blastocyst begins at day 5 in mammals after fertilization. This all occurs during the first week of being conceived. After the first week, the developing life form becomes an embryo, and the embryo is the stage where DNA is built..
A covalent chemical bond results from the sharing of electrons between two atoms with similar electronegativities A single covalent bond represent the sharing of two valence electrons (usually from two different atoms). The Lewis structure below represents the covalent bond between two hydrogen atoms in a H2 molecule.
a chemical bond. The two extreme cases of chemical bonds are: Covalent bond: bond in which one or more pairs of electrons are shared by two atoms. Ionic bond: bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.Other types of bonds include metallic bonds and hydrogen bonding. chemical bond. The two extreme cases of chemical bonds are: Covalent bond: bond in which one or more pairs of electrons are shared by two atoms. Ionic bond: bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.