Tutor profile: Tricia S.

Explain why specific elements or salt compounds with a specific metal, are used to create the varying colors in fireworks. For example, why is barium the metal used to produce green fireworks.

When an atom is heated, the electrons in the atom absorb that heat as energy and become "excited" and "jump" up to a higher energy level, which energy level and where is dependent on the specific element. Eventually, and rather quickly, the electrons release that absorbed energy, and return to their ground state. When they release the energy, they release it as photons, or light energy. The amount energy released, depends on the amount of energy that was needed to move the electron, it must be the same and is specific to an element. So the color(s) you see when a metal is heated, is due to the release of the energy, as photons (colors), that was absorbed in the first place to move the electrons to higher energy levels.

When writing a chemical formula or chemical name, what is the proper format for chemical nomenclature, for an ionic bond?

In chemical nomenclature, of ionic bonds, the metal is always named or identified first, and then the nonmetal. For example, in a compound of a sodium ion and chlorine ion, the sodium is the metal while the chlorine is the nonmetal. Therefore, we would put sodium before chloride, (remember: when a simple ionic compound is named we must change the ending to the nonmetal to -ide), so we would put for the chemical name: sodium chloride or for the chemical formule: NaCl.

Please explain the difference between a genotype and a phenotype.

Simply put the genotype, is the unique code in our genes that tells our genetics what trait we have, while the phenotype is the expression of that trait, or the trait itself. For example, the fur color of a Labrador retriever is based on a variation of an allele, or a premature stop codon on the allele. That premature stop codon on the allele is the genotype, while the actual yellow fur is the phenotype, the expression of the gene that we can see or experience.