Answer:
The polymerase chain reaction relies upon unusual, heat-resistant __DNA polymerase molecules______ that were isolated from bacteria living in hot springs.
Explanation:
A pair of genes that control a trait is referred to as an allele.
Answer:
B
Explanation:
For metals, the further away the valence electrons are from the nucleus, the higher the reactivity of the elements. Unlike halogens that are more reactive if the valence orbital shells are closer to the nucleus. This is due to ionization energies – which is the minimum energy required to discharge an electron from its orbit.
For metals this should be lower because they need to lose electrons to attain a stable electron configuration. For halogens it should be high because they don't need to lose electrons, but rather gain, in order to attain stable electron configuration.
Electrons in their orbital shells need to occur in pairs (with opposite quantum states) to be in stable configuration and as long as an atom has orbitals with single electrons, the atoms will be reactive as opposed to when its orbitals are ‘full’.
