Answer:
Cobalt Co
Explanation:
Co and Zn can fully replace each other, except perhaps for small individual requirements that are met by minute metal concentrations supplied as contaminants.
Answer:
Interactions between cells always involve a structure known as a connexins.
Explanation:
Connexins is composed of specific type of protein called transmembrane proteins. This structure is responsible for the interaction between the cells. Cells communicate with each other by secreting specific chemicals in which information is present. These chemicals consist of neurotransmitter and harmones.
Answer: C): the number of unpaired electrons.
Explanation: A covalent bond is a type of chemical bond formed by sharing equal number of electrons between two non-metal atoms so that both can attain the a stable octet or duplet structure of noble gases. The electrons shared by two non-metal atoms are the unpaired electrons. For example, in the formation of a chlorine molecule, a chlorine atom has seven valence electrons and electrons usually occur in pairs. Having seven valence electrons means that a chlorine atom has three pairs of electron and one unpaired electron in its outermost shell. The two chlorine atoms will combine together each donating its unpaired electron to be shared, thus leading the two atoms to attain stable octet structure of Argon.
