Answer these questions in terms of what you know about mixtures.
a. How would changing the proportions of substances in an alloy change its
properties?

Changing proportions of the substance in the alloy would changes the physical properties.

Explanation:

Physical properties of any substance is a collective representation of intensive and extensive properties. Intensive properties include density, conductivity, color, melleability, luster; however, extensive properties are mass, volume and length. by changing the proportions of the substance in the alloy, we would also change its physical properties. We know that alloy is nothing but a mixture of two or more metals. Therefore, different proportions will lead to different physical characteristics.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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