Consider the nuclear equation below.

Superscript 235 subscript 92 upper U right arrow superscript 4 subscript 2 upper H e.

What is the nuclide symbol of X?
Superscript 231 subscript 94 upper P u.
Superscript 235 subscript 90 upper T h.
Superscript 239 subscript 94 upper P u.
Superscript 231 subscript 90 upper T h.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

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.

gas

explanation:

smoke is the matter of a gas

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.