the answer is d hope this helps
Answer: (3) silicon
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: Silicon (Si)
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: ethane
, propanone
and water 
A sodium chloride is like most of the ionic compounds
existing here on earth in which they are composed of having a high melting
point and by this, if found in underground rock deposits, they are usually in a
form of solid.
Answer:
1.5M
Explanation:
Molarity = moles/volume
0.60 mol / 0.40 L = 1.5 M