What on a bird, besides it's feet, is chemically similar to scales?
a. beak
b. feathers
c. wings

besides bird's feet, Feathers are chemically similar to scales.

Explanation:

Even though Both Beaks and feathers are composed in their majority from keratin, a protein. They are differentiated by their functionality in a bird's body. Beaks are made to feed, attack, defend, and execute maintenance functions. While feathers are made to protect the dermis from temperature, sun, and other external elements as well as Scales. But the keratin factor that makes them similar is the alpha and beta keratin composition both have.

answer: e.   sour taste

explanation: acids are those substances which dissociates in water to give ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. acids are sour in taste. example: hcl

bases are those substances which dissociates in water to give ions or accepts ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. bases are bitter in taste. bases are slippery in nature.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.