Answer: 2. cannot be an element.
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper 
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: methane 
Thus as it can be decomposed into its constituent elements, it is a compound.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present.
Thus methane cannot be an element.
The elements in<span> groups 1a through 7a are called d. representative elements. The periodic table is organized according to increasing order of the atomic number of the elements. Groups have similar properties while the period of the elements determines the valence electrons in the outer shells.</span>
The product of reduction of ethyl 4-oxobutanoate with sodium borohydride in ethanol at room temperature for 30 minutes is ethyl 4- hydroxybutanoate .
Sodium borohydride is a relatively selective reducing agent Ethanolic solutions of Sodium borohydride reduces aldehyde , and ketone , in the presence of acid chloride , ester , epoxide , lactones , acids , nitriles , nitro groups.
The sodium borohydride does not reduce ester group because sodium borohydride is not strong enough and the electrophilicity at carbony carbon of ester is not more as compare toaldehyde , and ketone
The product of reduction of ethyl 4-oxobutanoate with sodium borohydride in ethanol at room temperature for 30 minutes is ethyl 4- hydroxybutanoate .
to learn more about sodium borohydride and ethanol click here ,
brainly.com/question/12955502
#SPJ4
<span>Colligative properties are dependent upon the number of molecules or ions present in solution. Therefore, 1 mole of Na2SO4 will produce 3 moles of ions and so it will have 3 times as much of an effect as 1 mole of sugar, which is not an electrolyte and can't dissociate to an appreciable extent.</span>
Answer:
good electrical conductor
lustre in appearance
